Modular semiconductor workpiece processing tool

ABSTRACT

The present invention provides for a semiconductor workpiece processing tool and methods for handling semiconductor workpiece therein. The semiconductor workpiece processing tool preferably includes an interface section comprising at least one interface module and a processing section comprising a plurality of processing modules for processing the semiconductor workpieces. The semiconductor workpiece processing tool may have a conveyor for transferring the semiconductor workpieces between the interface modules and the processing modules.

TECHNICAL FIELD

The present invention relates to tools for performing liquid and gaseousprocessing of semiconductor workpieces, and more particularly to toolswhich process semiconductor workpieces requiring low contaminant levels.

BACKGROUND OF THE INVENTION

Semiconductor workpieces, such as wafers and the like, are the subjectof extensive processing to produce integrated circuits, data disks andsimilar articles. During such processing it is often necessary to treata particular workpiece or workpiece surface with either gaseous orliquid chemicals. Such treatment allows for films or layers of materialto be deposited or grown on a workpiece surface. One method ofaccomplishing this is to expose the particular workpiece to desiredprocessing environments in which desired chemicals are present to formor grow such films or layers. Some processing regimes involve moving theworkpiece within the processing environment to effectuate film or layercoverage.

It has been increasingly desirable to minimize the size of features inintegrated circuits during such processing to provide circuits havingreduced size and increased integration and capacity. However, thereduction in feature size of such circuits is limited by contaminantssuch as particles, crystals, metals and organics which can cause defectsand render the circuit inoperational. These limitations in feature sizecaused by contaminants have prevented utilization of full resolutioncapability of known processing techniques.

It is therefore highly desirable to conduct such semiconductor workpieceprocessing within a regulated environment which preferably involves sometype of automated or computer controlled processing. The regulatedenvironment has minimal human contact to provide a low contaminantenvironment. Providing a regulated environment reduces the chances of aninadvertent contamination which could render the workpiece useless.

Therefore, an increased need exists for providing a processingenvironment which adequately performs semiconductor workpiece processingsteps in the presence of minimal contaminants.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the accompanying drawings, which are briefly describedbelow.

FIG. 1 is an isometric view of the semiconductor workpiece processingtool in accordance with the present invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of thesemiconductor workpiece processing tool shown in FIG. 1.

FIGS. 3-8 are a diagrammatic representation of a workpiece cassetteturnstile and elevator of a preferred interface module of thesemiconductor workpiece processing tool according to the presentinvention operating to exchange workpiece cassettes between a holdposition and an extraction position.

FIG. 9 is an isometric view of a preferred workpiece cassette trayengageable with the turnstile of an interface module of thesemiconductor workpiece processing tool.

FIG. 10 is an isometric view of an embodiment of a semiconductorworkpiece conveyor of the semiconductor workpiece processing tool inaccordance with the present invention.

FIG. 11 is a cross-sectional view taken along line 11-11 of thesemiconductor workpiece conveyor shown in FIG. 10.

FIG. 12 is a first isometric view of an embodiment of a semiconductorworkpiece transport unit of the semiconductor workpiece conveyor shownin FIG. 10.

FIG. 13 is a second isometric view of the semiconductor workpiecetransport unit shown in FIG. 12 with the cover thereof removed.

FIG. 14 is a functional block diagram of an embodiment of a controlsystem of the semiconductor workpiece processing tool in accordance withthe present invention.

FIG. 15 is a functional block diagram of a master/slave controlconfiguration of an interface module control subsystem for controlling aworkpiece cassette interface module of the processing tool.

FIG. 16 is a functional block diagram of an interface module controlsubsystem coupled with components of a workpiece cassette interfacemodule of the processing tool.

FIG. 17 is a functional block diagram of a workpiece conveyor controlsubsystem coupled with components of a workpiece conveyor of theprocessing tool.

FIG. 18 is a functional block diagram of a workpiece processing modulecontrol subsystem coupled with components of a workpiece processingmodule of the processing tool.

FIG. 19 is a functional block diagram of a stave processor of theinterface module control subsystem shown in FIG. 16 coupled withcomponents of a workpiece interface module of the processing tool.

FIG. 20 is a functional block diagram of a slave processor of theworkpiece conveyor control subsystem shown in FIG. 17 coupled withcomponents of a workpiece conveyor of the processing tool.

FIG. 21 is a functional block diagram of a slave processor of theworkpiece processing module control subsystem shown in FIG. 18 coupledwith components of a workpiece processing module of the processing tool.

FIG. 22 is an environmental view of the semiconductor processing head ofthe present invention showing two processing heads in a processingstation, one in a deployed, “closed” or “processing” position, and onein an “open” or “receive wafer” position.

FIG. 23 is an isometric view of the semiconductor processing head of thepresent invention.

FIG. 24 is a side elevation view of the processing head of the presentinvention showing the head in a “receive wafer” position.

FIG. 25 is a side elevation view of the processing head of FIG. 5showing the head in a rotated position ready to lower the wafer into theprocess station.

FIG. 26 is a side elevation view of the processing head of FIG. 5showing the head operator pivoted to deploy the processing head andwafer into the bowl of the process station.

FIG. 27 is a schematic front elevation view of the processing headindicating the portions detailed in FIGS. 28 and 29.

FIG. 28 is a front elevation sectional view of the left half of theprocessing head of the apparatus of the present invention also showing afirst embodiment of the wafer holding fingers.

FIG. 29 is a front elevation sectional view of the left half of theprocessing head of the apparatus of the present invention also showing afirst embodiment of the wafer holding fingers.

FIG. 30 is an isometric view of the operator base and operator arm ofthe apparatus of the present invention with the protective coverremoved.

FIG. 31 is a right side elevation view of the operator arm of thepresent invention showing the processing head pivot drive mechanism.

FIG. 32 is a left side elevation view of the operator arm of the presentinvention showing the operator arm drive mechanism.

FIG. 33 is schematic plan view of the operator arm indicating theportions detailed in FIGS. 34 and 35.

FIG. 34 is a partial sectional plan view of the right side of theoperator arm showing the processing head drive mechanism.

FIG. 35 is a partial sectional plan view of the left side of theoperator arm showing the operator arm drive mechanism.

FIG. 36 is a side elevational view of a semiconductor workpiece holderconstructed according to a preferred aspect of the invention.

FIG. 37 is a front sectional view of the FIG. 1 semiconductor workpieceholder.

FIG. 38 is a top plan view of a rotor which is constructed in accordancewith a preferred aspect of this invention, and which is taken along line3-3 in FIG. 37.

FIG. 39 is an isolated side sectional view of a finger assemblyconstructed in accordance with a preferred aspect of the invention andwhich is configured for mounting upon the FIG. 38 rotor.

FIG. 40 is a side elevational view of the finger assembly of FIG. 39.

FIG. 41 is a fragmentary cross-sectional enlarged view of a fingerassembly and associated rotor structure.

FIG. 42 is a view taken along line 7-7 in FIG. 4 and shows a portion ofthe preferred finger assembly moving between an engaged and disengagedposition.

FIG. 43 is a view of a finger tip of the preferred finger assembly andshows an electrode tip in a retracted or disengaged position (solidlines) and an engaged position (phantom lines) against a semiconductorworkpiece.

FIG. 44 is an isometric view of the apparatus of the present inventionshowing a five station plating module.

FIG. 45 is an isometric view of one embodiment of the apparatus of thesystem of FIG. 44 showing the internal components of the five unitplating module.

FIG. 46 is an isometric view showing the plating tank and the processbowls of the system of FIG. 44.

FIG. 47 is an isometric detail of a plating chamber of the apparatus ofthe present invention.

FIG. 48 is front elevation sectional view of the present inventionshowing the plating tank, the plating chambers, and the associatedplumbing.

FIG. 49 is side elevation sectional view of the present inventionshowing the plating tank and a plating chamber.

FIG. 50 is a side sectional view of the apparatus of the presentinvention showing a workpiece support positioned over an electroplatingprocess bowl.

FIG. 51 is a side sectional view of the apparatus of the presentinvention showing a workpiece support supporting a workpiece forprocessing within an electroplating process bowl.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8). TABLE 1 Listing ofSubsections of Detailed Description and Pertinent Items with ReferenceNumerals and Page Numbers Processing Tool Generally 12 semiconductorworkpiece processing 12 tool 10 interface section 12 13 processingsection 14 13 workpiece cassettes 16 13 first port 32 13 second port 3313 powered doors 35, 36 13 plating module 20 14 pre-wet module 22 14resist strip module 24 14 rear closure surface 18 15 air supply 26 15exhaust ducts 58, 59 15 frame 65 15 workpiece transport unit guide 66 15workpiece transport units 62, 64 16 user interface 30 17 window 34 17vents 37 17 two interface modules 38, 39 18 workpiece cassette turnstile40, 41 18 workpiece cassette elevator 42, 43 18 workpiece cassettesupport 47, 48 18 semiconductor workpiece conveyor 60 19 workpieceholder 810 19 workpiece support 401 20 finger assemblies 409 20Interface Module 22 saddles 45, 46 23 turnstile shaft 49 24 poweredshaft 44 25 Workpiece Cassette Tray 26 workpiece cassette tray 50 26base 51 26 upright portion 54 26 lateral supports 52 26 groove 53 26Semiconductor Workpiece Conveyor 27 paths of movement 68, 70 28 guiderails 63, 64 28 Extensions 69, 75 28 drive operators 71, 74 28electromagnet 79 29 Cable guards 72, 73 29 linear bearing 76 29horizontal roller 77 29 Semiconductor Workpiece Transport Units 30 train84 30 workpiece transfer arm assembly 86 30 workpiece transfer armelevator 90 30 cover 85 30 first arm extension 87 30 shaft 83 30 secondarm extension 88 31 axis 82 31 wafer support 89 31 light or other beamemitter 81 32 CCD array 91 32 Control System Generally 32 control system100 32 grand master controller 101 33 interface module control 110 33conveyor control 113 33 processing module controls 114, 115 33additional grand master controllers 102 33 additional processing modulecontrol 34 119 memory mapped devices 160, 161, 162 34 master controllers130, 131, 132 34 Master/Slave Configuration 35 data link 126, 127, 129as shown in FIG. 36 16-FIG. 18 slave controllers 140, 141, 142 36turnstile motor 185 38 incremental turnstile encoder 190 38 saddle motor186 38 saddle encoder 191 38 Conveyor Control Subsystem 39 slaveprocessor 171 40 servo controller 176 40 linear encoder 196 40 transferarm motor 194 40 transfer arm rotation encoder 197 40 transfer armelevation motor 195 41 transfer arm elevation encoder 198 41 Absoluteencoders 199 41 Processing Module Control 41 slave controller 145, 14642 process components 184 42 servo controller 177 42 interfacecontroller 180 42 slave processor 172 43 servo controller 177 43operator arm 407 43 lift drive shaft 456 43 lift motion encoder 455 43lift arm 407 43 rotate motor 428 43 processing head 406 43 shafts 429,430 43 Incremental rotate encoder 435 43 Spin motor 480 43 workpieceholder 478 43 spin encoder 498 43 fingertips 414 43 pneumatic valveactuator 201 43 pneumatic piston 502 43 relay 202 44 pump 605 44Interface Module Control 45 Slave processor 170 45 servo controller 17546 elevator lift motor 187 46 elevator rotation motor 188 46 ift encoder192 47 rotation encoder 193 47 Absolute encoders 199 47 Methods 47Workpiece Support 49 semiconductor processing machine 400 49 workpiecesupports 401 49 Workpiece support 402 49 Workpiece support 403 50semiconductor manufacturing chamber 50 404 beam emitter 81 50 operatorbase 405 50 processing head 406 50 operator arm 407 50 wafer holder 40850 fingers 409 50 Workpiece holder 408 50 workpiece spin axis 410 50process pivot axis 411 50 operator pivot axis 412 50 workpiece W 51fingertips 414 51 51 processing bowl 417 51 left and rigbt forks 418 and419 52 Operator Base 52 operator base back portion 420 52 operator baseleft yoke arm 421 53 operator base right yoke arm 422 53 yoke armfasteners 423 53 operator arm bearings 424 53 operator arm 425 53Operator Arm 53 process arm rear cavity 426 54 lift motor 452 54 rotatemotor 428 54 processing head left pivot shaft 429 54 processing headright pivot shaft 430 54 Operator Arm-Processing Head Rotate Mechanism54 Processing head rotate mechanism 431 54 rotate shaft 432 54 securingcollar 433 55 rotate motor support 434 55 rotate encoder 435 55 rotatepulley inboard bearing 436 56 rotate belt 437 56 processing head pulley438 56 rotate belt tensioner 439 56 tensioner hub 468 57 processing headshaft bearing 440 57 processing head rotate bearing 469 57 processinghead shaft bearing 441 57 cable brackets 442 and 443 57 rotateovertravel protect 444 58 rotate flag 447 58 Rotate optical switches 445and 446 59 Operator Arm-Lift Mechanism 59 operator arm lift mechanism448 59 lift motor shaft 454 59 lift gear drive 453 60 lift drive shaft456 60 lift bushing 449 60 anchor plate 458 60 anchor fasteners 457 6060 Lift bearing 450 60 lift bearing support 460 60 operator arm frame461 60 lift anchor 451 61 lift overtravel protect 462 61 lift opticalswitch low 463 61 lift optical switch high 464 61 lift flag 465 62 liftmotor encoder 455 62 lift motor 452 62 slotted lift flag mounting slots467 62 lift flag fasteners 466 62 Processing Head 62 processing headhousing 470 63 circumferential grooves 471 63 rotate shaft openings 474and 475 63 left and right processing head mounts 63 472 processing headdoor 476 63 processing head void 477 63 Processing Head Spin Motor 64workpiece holder 478 64 spin axis 479 64 spin motor 480 64 top motorhousing 481 65 spin motor shaft 483 65 workpiece holder rotor 484 65 65rotor hub 485 65 rotor hub recess 486 65 workpiece shaft snap-ring 48865 rotor recess-groove 489 65 spin encoder 498 66 optical tachometer 49966 Processing Head Finger Actuators 68 Pneumatic piston 502 69 actuatorspring 505 69 cavity end cap 507 69 retaining ring 508 69 pneumaticinlet 503 69 pneumatic supply line 504 69 actuator plate 509 69 actuatorplate connect screw 510 69 Wave springs 529 69 bushing 512 69 pneumaticpiston recess 511 69 finger actuator contacts 513 70 Processing HeadWorkpiece Holder 70 finger actuator lever 514 70 finger stem 515 70finger diaphragm 519 70 workpiece holder rotor 484 71 finger opening 52171 rotor diaphragm lip 523 71 finger spring 520 71 finger actuator tab522 71 finger collar or nut 517 71 518 71 finger actuator mechanism 50071 cavity 501 72 Semiconductor Workpiece Holder — ElectroplatingEmbodiment 72 semiconductor workpiece holder 810 72 bottom half or bowl811 73 Processing Head and Processing Head Operator 73 workpiece support812 73 spin head assembly 814 73 lift/rotate assembly 816 73 motor 81874 rotor 820 74 rotor spin axis 822 74 finger assembly 824 74 actuator825 75 rotor center piece 826 75 spokes 828 75 rotor perimeter piece 83075 Finger Assembly 76 finger assembly frame 832 77 angled slot 832a 77finger assembly frame outer flange 834 77 inner drive plate portion 83677 Finger Assembly Drive System 77 bearing 838 77 collet 840 77 bearingreceptacle 839 77 spring 842 78 spring seat 844 78 Finger AssemblyElectrical System 78 pin connector 846 79 finger 848 79 nut 850 79anti-rotation pin 852 79 finger tip 854 79 electrode contact 858 80Finger Assembly Drive System Interface 80 finger actuator 862 80 863 80first movement path axis 864 81 secondary linkage 865 81 link arm 867 81actuator torque ring 869 81 pneumatic operator 871 81 Engaged andDisengaged Positions 82 arrow A 82 workpiece standoff 865 83 bend 866 83Finger Assembly Seal 84 868 84 rim portion 870 84 Methods and Operation85 Methods Re Presenting Workpiece 88 Electroplating Processing Station91 electroplating module 20 91 workpiece support 401 92 processing head406 92 operator arm 407 92 operator base 405 92 fingers 409 92 beamemitter 81 93 plating chamber assemblies 603 93 process fluid reservoir604 93 immersible pump 605 93 module frame or chassis 606 93 pumpdischarge filter 607 93 outer reservoir wall 608 93 inner reservoir wall609 93 reservoir safety volume 611 94 inner vessel 612 94 reservoiroverflow opening 610 94 heat exchanger 613 94 exchanger inlet 614 94exchanger outlet 615 94 Bowl Assembly 94 reservoir top 618 95 processbowl or plating chamber 616 95 bowl side 617 95 bowl bottom 619 95 cupassembly 620 95 fluid cup 621 95 cup side 622 95 cup bottom 623 95 fluidinlet line 625 95 bowl bottom opening 627 95 cup fluid inlet opening 62495 inlet line end point 631 95 Fluid outlet openings 628 95 inlet plenum629 95 cup filter 630 95 metallic anode 634 96 annular gap or space 63596 outer cup wall 636 96 first annular space or process fluid 96overflow space 632 cup upper edge 633 96 bowl upper edge 637 96crossbars 626 97 bowl bottom center plate 639 97 fluid return openings638 97 process module deck plate 666 99 levelers 640 99 compliant bowlseal 665 100 cup height adjuster 641 100 cup height adjustment jack 643100 cup lock nut 642 100 height adjustment jack 641 100 adjustment toolaccess holes 667 100 anode height adjuster 646 101 threaded anode post664 101 threaded anode adjustment sleeve 663 101 sleeve openings 668 101fluid outlet chamber 662 101 Fluid Transfer Equipment 102 pump suction647 102 pump body 653 102 pump discharge 648 102 Electric pump motor 650102 removable filter top 649 103 supply manifold 652 103 fluid returnline 654 103 optional end point 655 103 back pressure regulator 656 103Control Devices 104 flow sensors 657 104 flow signal line 659 104 flowrestrictors 658 104 flow control signal line 660 104 Plating Methods 105Processing Tool Generally

Referring to FIG. 1, a present preferred embodiment of the semiconductorworkpiece processing tool 10 is shown. The processing tool 10 maycomprise an interface section 12 and processing section 14.Semiconductor workpiece cassettes 16 containing a plurality ofsemiconductor workpieces, generally designated W, may be loaded into theprocessing tool 10 or unloaded therefrom via the interface section 12.In particular, the workpiece cassettes 16 are preferably loaded orunloaded through at least one port such as first port 32 within a frontoutwardly facing wall of the processing tool 10. An additional secondport 33 may be provided within the interface section 12 of theprocessing tool 10 to improve access and port 32 may be utilized as aninput and port 33 may be utilized as an output.

Respective powered doors 35, 36 may be utilized to cover access ports32, 33 thereby isolating the interior of the processing tool 10 from theclean room. Each door 35, 36 may comprise two portions. The upperportions and lower portion move upward and downward, respectively, intothe front surface of the processing tool 10 to open ports 32, 33 andpermit access therein.

Workpiece cassettes 16 are typically utilized to transport a pluralityof semiconductor workpieces. The workpiece cassettes 16 are preferablyoriented to provide the semiconductor workpieces therein in an uprightor vertical position for stability during transportation of thesemiconductor workpieces into or out of the processing tool 10.

The front outwardly facing surface of the processing tool 10 mayadvantageously join a clean room to minimize the number of harmfulcontaminants which may be introduced into the processing tool 10 duringinsertion and removal of workpiece cassettes 16. In addition, aplurality of workpiece cassettes 16 may be introduced into processingtool 10 or removed therefrom at one time to minimize the opening ofports 32, 33 and exposure of the processing tool 10 to the clean roomenvironment.

The interface section 12 joins a processing section 14 of the processingtool 10. The processing section 14 may include a plurality ofsemiconductor workpiece processing modules for performing varioussemiconductor process steps. In particular, the embodiment of theprocessing tool 10 shown in FIG. 1 includes a plating module 20 defininga first lateral surface of the processing section 14. The processingsection 14 of the tool 10 may advantageously include additional modules,such as pre-wet module 22 and resist strip module 24, opposite theplating module 20.

Alternatively, other modules for performing additional processingfunctions may also be provided within the processing tool 10 inaccordance with the present invention. Pre-wet module 22 and resiststrip module 24 define a second lateral surface of the processing tool10. The specific processing performed by processing modules of theprocessing tool 10 may be different or of similar nature. Various liquidand gaseous processing steps can be used in various sequences. Theprocessing tool 10 is particularly advantageous in allowing a series ofcomplex processes to be run serially in different processing modules setup for different processing solutions. All the processing can beadvantageously accomplished without human handling and in a highlycontrolled working space 11, thus reducing human operator handling timeand the chance of contaminating the semiconductor workpieces.

The processing modules of the process tool 10 in accordance with thepresent invention are preferably modular, interchangeable, stand-aloneunits. The processing functions performed by the processing tool 10 maybe changed after installation of the processing tool 10 increasingflexibility and allowing for changes in processing methods. Additionalworkpiece processing modules may be added to the processing tool 10 orreplace existing processing modules 19.

The processing tool 10 of the present invention preferably includes arear closure surface 18 joined with the lateral sides of the processingtool 10. As shown in FIG. 1, an air supply 26 may be advantageouslyprovided intermediate opposing processing modules of the processingsection 14. The interface section 12, lateral sides of the processingsection 14, closure surface 18, and air supply 26 preferably provide anenclosed work space 11 within the processing tool 10. The air supply 26may comprise a duct coupled with a filtered air source (not shown) forproviding clean air into the processing tool 10 of the presentinvention. More specifically, the air supply 26 may include a pluralityof vents intermediate the processing modules 19 for introducing cleanair into work space 11.

Referring to FIG. 10, exhaust ducts 58, 59 may be provided adjacent theframe 65 of a workpiece transport unit guide 66 to remove the circulatedclean air and the contaminants therein. Exhaust ducts 58, 59 may becoupled with the each of the processing modules 19 for drawing suppliedclean air therethrough. In particular, clean air is supplied to theworkspace 11 of the processing tool 10 via air supply 26. The air may bedrawn adjacent the workpiece transport units 62, 64 and into theprocessing modules 19 via a plurality of vents 57 formed within a shelfor process deck thereof by an exhaust fan (not shown) coupled with theoutput of exhaust ducts 58, 59. Each processing module 19 within theprocessing tool 10 may be directly coupled with ducts 58, 59. The airmay be drawn out of the ducts 58, 59 of the processing tool 10 throughthe rear closant surface 18 or through a bottom of surface of theprocessing tool 10. Providing an enclosed work space and controlling theenvironment within the work space greatly reduces the presence ofcontaminants with the processing tool 10.

Each of the processing modules 20, 22, 24 may be advantageously accessedthrough the rear panel of the respective module forming the lateral sideof the processing tool 10. The lateral sides of the processing tool 10may be adjacent a gray room environment. Gray rooms have fewerprecautions against contamination compared with the clean rooms.Utilizing this configuration reduces plant costs while allowing accessto the processing components and electronics of each workpiece module 19of the processing tool 10 which require routine maintenance.

A user interface 30 may be provided at the outwardly facing frontsurface of the processing tool as shown in FIG. 1. The user interface 30may advantageously be a touch screen cathode ray tube control displayallowing finger contact to the display screen to effect various controlfunctions within the processing tool 10. An additional user interface 30may also be provided at the rear of the processing tool 10 or withinindividual processing modules 20, 22, 24 so that processing tool 10operation can be effected from alternate locations about the processingtool 10. Further, a portable user interface 30 may be provided to permitan operator to move about the processing tool 10 and view the operationof the processing components therein. The user interface 30 may beutilized to teach specified functions and operations to the processingmodules 19 and semiconductor workpiece transport units 62, 64.

Each module 20, 22, 24 within the processing tool 10 preferably includesa window 34 allowing visual inspection of processing tool 10 operationfrom the gray room. Further, vents 37 may be advantageously providedwithin a top surface of each processing module 20, 22, 24. Processingmodule electronics are preferably located adjacent the vents 37 allowingcirculating air to dissipate heat generated by such electronics.

The work space 11 within the interface section 12 and processing section14 of an embodiment of the processing tool 10 is shown in detail in FIG.2.

The interface section 12 includes two interface modules 38, 39 formanipulating workpiece cassettes 16 within the processing tool 10. Theinterface modules 38, 39 receive workpiece cassettes 16 through theaccess ports 32, 33 and may store the workpiece cassettes 16 forsubsequent processing of the semiconductor workpieces therein. Inaddition, the interface modules 38, 39 store the workpiece cassettes forremoval from the processing tool 10 upon completion of the processing aof the semiconductor workpieces within the respective workpiece cassette16.

Each interface module 38, 39 may comprise a workpiece cassette turnstile40, 41 and a workpiece cassette elevator 42, 43. The workpiece cassetteturnstiles 40, 41 generally transpose the workpiece cassettes 16 from astable vertical orientation to a horizontal orientation where access tothe semiconductor workpieces is improved. Each workpiece cassetteelevator 42, 43 has a respective workpiece cassette support 47, 48 forholding workpiece cassettes 16. Each workpiece cassette elevator 42, 43is utilized to position a workpiece cassette 16 resting thereon ineither a transfer position and extraction position. The operation of theworkpiece interface modules 38, 39 is described in detail below.

In a preferred embodiment of the present invention, the first workpieceinterface module 38 may function as an input workpiece cassetteinterface for receiving unprocessed semiconductor workpieces into theprocessing tool 10. The second workpiece interface module 39 mayfunction as an output workpiece cassette interface for holding processedsemiconductor workpieces for removal from the processing tool 10.Workpiece transport units 62, 64 within the processing tool 10 mayaccess workpiece cassettes 16 held by either workpiece interface module38, 39. Such an arrangement facilitates transferring of semiconductorworkpieces throughout the processing tool 10.

A semiconductor workpiece conveyor 60 is shown intermediate processingmodules 20, 22, 24 and interface modules 38, 39 in FIG. 2. The workpiececonveyor 60 includes workpiece transport units 62, 64 for transferringindividual semiconductor workpieces W between each of the workpieceinterface modules 38, 39 and the workpiece processing modules 19.

Workpiece conveyor. 60 advantageously includes a transport unit guide66, such as an elongated rail, which defines a plurality of paths 68, 70for the workpiece transport units 62, 64 within the processing tool 10.A workpiece transport unit 62 on a first path 68 may pass a workpiecetransport unit 64 positioned on a second path 70 during movement of thetransport units 62, 64 along transport guide 66. The processing tool 10may include additional workpiece transport units to facilitate thetransfer of semiconductor workpieces W between the workpiece processingmodules 20, 22, 24 and workpiece interface modules 38, 39.

Each processing module 20, 22, 24 includes at least one semiconductorworkpiece holder such as workpiece holder 810 located generally adjacentthe workpiece conveyor 60. In particular, each of the workpiecetransport units 62, 64 may deposit a semiconductor workpiece upon asemiconductor workpiece support 401 of the appropriate semiconductorprocessing module 20, 22, 24. Specifically, workpiece transport unit 64is shown accessing an semiconductor workpiece support 401 of processingmodule 20. The workpiece transport units may either deposit or retrieveworkpieces on or from the workpiece supports 401.

More specifically, the second arm extension 88 may support asemiconductor workpiece W via vacuum support 89. The appropriateworkpiece transport unit 62, 64 may approach a workpiece support 401 bymoving along transport unit guide 66. After reaching a proper locationalong guide 66, the first extension 87 and second extension 88 mayrotate to approach the workpiece support 401. The second extension 88 ispositioned above the workpiece support 401 and subsequently loweredtoward engagement finger assemblies 409 on the workpiece support 401.The vacuum is removed from vacuum support 89 and finger assemblies 409grasp the semiconductor workpiece W positioned therein. Second extension88 may be lowered and removed from beneath the semiconductor workpieceheld by the workpiece engagement fingers.

Following completion of processing of the semiconductor workpiece withinthe appropriate processing module 20, 22, 24, a workpiece transport unit62, 64 may retrieve the workpiece and either deliver the workpiece toanother processing module 20, 22, 24 or return the workpiece to aworkpiece cassette 16 for storage or removal from the processing tool10.

Each of the workpiece transport units 62, 64 may access a workpiececassette 16 adjacent the conveyor 60 for retrieving a semiconductorworkpiece from the workpiece cassette 16 or depositing a semiconductorworkpiece therein. In particular, workpiece transport unit 62 is shownwithdrawing a semiconductor workpiece W from workpiece cassette 16 uponelevator 42 in FIG. 2.

More specifically, the second extension 88 and vacuum support 89connected therewith may be inserted into a workpiece cassette 16positioned in the extraction position. Second extension 88 and vacuumsupport 89 enter below the lower surface of the bottom semiconductorworkpiece W held by workpiece cassette 16. A vacuum may be applied viavacuum support 89 once support 89 is positioned below the center of thesemiconductor workpiece W being removed. The second extension 88, vacuumsupport 89 and semiconductor workpiece W attached thereto may beslightly raised via transfer arm elevator 90. Finally, first extension87 and second extension 88 may be rotated to remove the semiconductorworkpiece W from the workpiece cassette 16. The workpiece transport unit62, 64 may thereafter deliver the semiconductor workpiece W to aworkpiece processing module 19 for processing.

Thereafter, workpiece transport unit 62 may travel along path 68 to aposition adjacent an appropriate processing module 20, 22, 24 fordepositing the semiconductor workpiece upon workpiece processing support401 for processing of the semiconductor workpiece.

Interface Module

Referring to FIG. 3-FIG. 8, the operation of the interface module 38 isshown in detail. The following discussion is limited to workpieceinterface module 38 but is also applicable to workpiece interface module39 inasmuch as each interface module 38, 39 may operate in substantiallythe same manner.

Preferably, the first workpiece interface module 38 and the secondworkpiece interface module 39 may function as a respective semiconductorworkpiece cassette 16 input module and output module of the processingtool 10. Alternately, both modules can function as both input andoutput. More specifically, workpiece cassettes 16 holding unprocessedsemiconductors workpieces may be brought into the processing tool 10 viaport 32 and temporarily stored within the first workpiece interfacemodule 38 until the semiconductor workpieces are to be removed from theworkpiece cassette 16 for processing. Processed semiconductor workpiecesmay be delivered to a workpiece cassette 16 within the second workpieceinterface module 39 via workpiece transport units 62, 64 for temporarystorage and/or removal from the processing tool 10.

The workpiece interface modules 38, 39 may be directly accessed by eachof the workpiece transport units 62, 64 within the processing tool 10for transferring semiconductor workpieces therebetween. Providing aplurality of workpiece cassette interface modules 38, 39 accessible byeach workpiece transport unit 62, 64 facilitates the transport ofsemiconductor workpieces W throughout the processing tool 10 accordingto the present invention.

Each workpiece interface module 38, 39 preferably includes a workpiececassette turnstile 40 and a workpiece cassette elevator 42 adjacentthereto. The access ports 32, 33 are adjacent the respective workpiececassette turnstiles 40, 41. Workpiece cassettes 16 may be brought intothe processing tool 10 or removed therefrom via ports 32, 33.

Workpiece cassettes 16 are preferably placed in a vertical position ontocassette Frays 50 prior to delivery into the processing tool 10.Cassette trays 50 are shown in detail in FIG. 9. The vertical positionof workpiece cassettes 16 and the semiconductor workpieces thereinprovides a secure orientation to maintain the semiconductor workpieceswithin the workpiece cassette 16 for transportation.

Each workpiece cassette turnstile 40, 41 preferably includes two saddles45, 46 each configured to hold a workpiece cassette 16. Providing twosaddles 45, 46 enables two workpiece cassettes 16 to be placed into theprocessing tool 10 or removed therefrom during a single opening of arespective access door 35, 36 thereby minimizing exposure of theworkspace 11 within the processing tool 10 to the clean roomenvironment.

Each saddle 45, 46 includes two forks engageable with the cassette tray50. Saddles 45, 46 are powered by motors within the workpiece cassetteturnstile shaft 49 to position the workpiece cassette 16 in a horizontalor vertical orientation. The workpiece cassettes 16 and semiconductorworkpieces therein are preferably vertically oriented for passagethrough the access ports 32, 33 and horizontally oriented in a transferor extraction position to provide access of the workpieces therein tothe workpiece transport units 62, 64.

The workpiece cassette 16 held by workpiece cassette turnstile 40 inFIG. 3, also referred to as workpiece cassette 15, is in a hold position(also referred to herein as a load position). The semiconductorworkpieces within a workpiece cassette 16 in the hold position may bestored for subsequent processing. Alternatively, the semiconductorworkpieces within a workpiece cassette 16 in the hold position may bestored for subsequent removal from the processing tool 10 through anaccess port 32, 33.

Referring to FIG. 3, the workpiece cassette 16 supported by theworkpiece cassette elevator 42, also referred to as workpiece cassette17, is in an extraction or exchange position. Semiconductor workpiecesmay either be removed from or placed into a workpiece cassette 16positioned in the extraction position via a workpiece transport unit 62,64.

The workpiece cassette turnstile 41 and workpiece cassette elevator 42may exchange workpiece cassettes 15, 17 to transfer a workpiece cassette17 having processed semiconductor workpieces therein from the extractionposition to the hold position for removal from the processing tool 10.Additionally, such an exchange may transfer a workpiece cassette 15having unprocessed semiconductor workpieces therein from the holdposition to the extraction position providing workpiece transport units62, 64 with access to the semiconductor workpiece therein.

The exchange of workpiece cassettes 15, 17 is described with referenceto FIG. 4-FIG. 8. Specifically, saddle 46 is positioned below a poweredshaft 44 of workpiece cassette elevator 42. Shaft 44 is coupled with apowered workpiece cassette support 47 for holding a workpiece cassette16. Shaft 44 and workpiece cassette support 47 attached thereto arelowered as shown in FIG. 4 and shaft 44 passes between the forks ofsaddle 46.

Referring to FIG. 5, a motor within shaft 44 rotates workpiece cassettesupport 47 about an axis through shaft 44 providing the workpiececassette 17 thereon in an opposing relation to the workpiece cassette 15held by workpiece cassette turnstile 40. Both saddles 45, 46 ofworkpiece cassette turnstile 40 are subsequently tilted into ahorizontal orientation as shown in FIG. 6. The shaft 44 of workpiececassette elevator 42 is next lowered and workpiece cassette 17 isbrought into engagement with saddle 46 as depicted in FIG. 7. The shaft44 and workpiece cassette support 47 are lowered an additional amount toclear rotation of workpiece cassettes 16. Referring to FIG. 8, workpiececassette turnstile 40 rotates 180 degrees to transpose workpiececassettes 15, 17.

Workpiece cassette 17 having processed semiconductor workpieces thereinis now accessible via port 32 for removal from the processing tool 10.Workpiece cassette 15 having unprocessed semiconductors therein is nowpositioned for engagement with workpiece cassette support 47. Thetransfer process steps shown in FIG. 3-FIG. 8 may be reversed to elevatethe workpiece cassette 15 into the extraction position providing accessof the semiconductor workpieces to workpiece transport units 62, 64.

Workpiece Cassette Tray

A workpiece cassette tray 50 for holding a workpiece cassette 16 isshown in detail in FIG. 9. Each cassette tray 50 may include a base 51and an upright portion 54 preferably perpendicular to the base 51. Twolateral supports 52 may be formed on opposing sides of the base 51 andextend upward therefrom. Lateral supports 52 assist with maintainingworkpiece cassettes 16 thereon in a fixed position during the movement,rotation and exchange of workpiece cassettes 16. Each lateral support 52contains a groove 53 preferably extending the length thereof configuredto engage with the forks of saddles 45, 46.

The workpiece cassette trays 50 are preferably utilized during thehandling of workpiece cassettes 16 within the workpiece cassetteinterface modules 38, 39 where the workpiece cassettes 16 aretransferred from a load position to an extraction position providingaccess of the semiconductor workpieces W to workpiece transport units62, 64 within the conveyor 60.

Semiconductor Workpiece Conveyor

The processing tool 10 in accordance with the present inventionadvantageously provides a semiconductor workpiece conveyor 60 fortransporting semiconductor workpieces throughout the processing tool 10.Preferably, semiconductor workpiece conveyor 60 may access eachworkpiece cassette interface module 38, 39 and each workpiece processingmodule 19 within processing tool 10 for transferring semiconductorworkpieces therebetween. This includes processing modules from eitherside.

One embodiment of the workpiece conveyor 60 is depicted in FIG. 10. Theworkpiece conveyor 60 generally includes a workpiece transport unitguide 66 which preferably comprises an elongated spine or rail mountedto frame 65. Alternatively, transport unit guide 66 may be formed as atrack or any other configuration for guiding the workpiece transportunits 62, 64 thereon. The length of workpiece conveyor 60 may be variedand is configured to permit access of the workpiece transport units 62,64 to each interface module 38, 39 and processing modules 20, 22, 24.

Workpiece transport unit guide 66 defines the paths of movement 68, 70of workpiece transport units 62, 64 coupled therewith. Referring to FIG.11, a spine of transport unit guide 66 includes guide rails 63, 64mounted on opposite sides thereof. Each semiconductor workpiecetransport unit 62, 64 preferably engages a respective guide rail 63, 64.Each guide rail can mount one or more transport units 62, 64. Extensions69, 75 may be fixed to opposing sides of guide 66 for providingstability of the transport units 62, 64 thereagainst and to protectguide 66 from wear. Each workpiece transport unit 62, 64 includes aroller 77 configured to ride along a respective extension 69, 75 ofguide 66.

It is to be understood that workpiece conveyor 60 may be formed inalternate configurations dependent upon the arrangement of interfacemodules 38, 39 and processing modules 20, 22, 24 within the processingtool 10. Ducts 58, 59 are preferably in fluid communication withextensions from each workpiece processing module 19 and an exhaust fanfor removing circulated air from the workspace 11 of the processing tool10.

Each workpiece transport unit 62, 64 is powered along the respectivepath 68, 70 by a suitable driver. More specifically, drive operators 71,74 are advantageously mounted to respective sides of transport unitguide 66 to provide controllable axial movement of workpiece transportunits 62, 64 along the transport unit guide 66.

The drive operators 71, 74 may be linear magnetic motors for providingprecise positioning of workpiece transport units 62, 64 along guide 66.In particular, drive operators 71, 74 are preferably linear brushlessdirect current motors. Such preferred driver operators 71, 74 utilize aseries of angled magnetic segments which magnetically interact with arespective electromagnet 79 mounted on the workpiece transport units 62,64 to propel the units along the transport unit guide 66.

Cable guards 72, 73 may be connected to respective workpiece transportunits 62, 64 and frame 65 for protecting communication and power cablestherein. Cable guards 72, 73 may comprise a plurality of interconnectedsegments to permit a full range of motion of workpiece transport units62, 64 along transport unit guide 66.

As shown in FIG. 11, a first workpiece transport unit 62 is coupled witha first side of the spine of guide 66. Each workpiece transport unit 62,64 includes a linear bearing 76 for engagement with linear guide rails63, 64. Further, the workpiece transport units 62, 64 each preferablyinclude a horizontal roller 77 for engaging a extension 69 formed uponthe spine of the guide 66 and providing stability.

FIG. 11 additionally shows an electromagnet 79 of the first workpiecetransport unit 62 mounted in a position to magnetically interact withdrive actuator 71. Drive actuator 71 and electromagnet 79 provide axialmovement and directional control of the workpiece transport units 62, 64along the transport unit guide 66.

Semiconductor Workpiece Transport Units

Preferred embodiments of the semiconductor workpiece transport units 62,64 of the workpiece conveyor 60 are described with reference to FIG. 12and FIG. 13.

In general, each workpiece transport unit 62, 64 includes a movablecarriage or tram 84 coupled to a respective side of the transport unitguide 66, a workpiece transfer arm assembly 86 movably connected to thetram 84 for supporting a semiconductor workpiece W, and a workpiecetransfer arm elevator 90 for adjusting the elevation of the transfer armassembly 86 relative to tram 84.

Referring to FIG. 12, a cover 85 surrounds the portion of tram 84 facingaway from the transport unit guide 66. Tram 84 includes linear bearings76 for engagement With respective guide rails 63, 64 mounted totransport unit guide 66. Linear bearings 76 maintain the tram 84 in afixed relation with the transport unit guide 66 and permit axialmovement of the tram 84 therealong. A roller 77 engages a respectiveextension 69 for preventing rotation of tram 84 about guide rail 63, 64and providing stability of workpiece transport unit 62. Theelectromagnet 79 is also shown connected with the tram 84 in such aposition to magnetically interact with a respective transport unit 62,64 drive actuator 71, 74.

A workpiece transfer arm assembly 86 extends above the top of tram 84.The workpiece transfer arm assembly 86 may include a first arm extension87 coupled at a first end thereof with a shaft 83. A second armextension 88 may be advantageously coupled with a second end of thefirst extension 87. The first arm extension 87 may rotate 360 degreesabout shaft 83 and second arm extension 88 may rotate 360 degrees aboutaxis 82 passing through a shaft connecting first and second armextensions 87, 88.

Second extension 88 preferably includes a wafer support 89 at a distalend thereof for supporting a semiconductor workpiece W during thetransporting thereof along workpiece conveyor 60. The transfer armassembly 86 preferably includes a chamber coupled with the workpiecesupport 89 for applying a vacuum thereto and holding a semiconductorworkpiece W thereon.

Providing adjustable elevation of transfer arm assembly 86, rotation offirst arm extension 87 about the axis of shaft 83, and rotation ofsecond extension 88 about axis 82 allows the transfer arm 86 to accesseach semiconductor workpiece holder 810 of all processing modules 19 andeach of the wafer cassettes 16 held by interface modules 38, 39 withinthe processing tool 10. Such access permits the semiconductor workpiecetransport units 62, 64 to transfer semiconductor workpiecestherebetween.

The cover 85 has been removed from the workpiece transport unit 62, 64shown in FIG. 13 to reveal a workpiece transfer arm elevator 90 coupledwith tram 84 and transfer arm assembly 86. Transfer arm elevator 90adjusts the vertical position of the transfer arm assembly 86 relativeto the tram 84 during the steps of transferring a semiconductorworkpiece between the workpiece support 89 and one of a workpiece holder810 and the workpiece cassette 16.

The path position of the tram 84 of each workpiece transport unit 62, 64along the transport unit guide 66 is precisely controlled using apositional indicating array, such as a CCD array 91 of FIG. 13. In oneembodiment of the processing tool 10, each semiconductor workpieceholder 810 within a processing module 19 has a corresponding light orother beam emitter 81 mounted on a surface of the processing module 19as shown in FIG. 2 for directing a beam of light toward the transportunit guide 66. The light emitter 81 may present a continuous beam oralternatively may be configured to generate the beam as a workpiecetransport unit 62, 64 approaches the respective workpiece holder 810.

The transfer arm assembly 86 includes an CCD array 91 positioned toreceive the laser beam generated by light emitter 81. A positionindicating array 91 on shaft 83 detects the presence of the light beamto determine the location of tram 84 along transport unit guide 66. Thepositional accuracy of the workpiece transport unit position indicatoris preferably in the range less than 0.003 inch (approximately less than0.1 millimeter).

Control System Generally

Referring to FIG. 14, a presently preferred embodiment of the controlsystem 100 of the semiconductor workpiece processing tool 10 inaccordance with the present invention generally includes at least onegrand master controller 101 for controlling and/or monitoring theoverall function of the processing tool 10.

The control system 100 is preferably arranged in a hierarchialconfiguration. The grand master controller 101 includes a processorelectrically coupled with a plurality of subsystem control units asshown in FIG. 14. The control subsystems preferably control and monitorthe operation of components of the corresponding apparatus (i.e.,workpiece conveyor 60, processing modules 20, 22, 24, interface modules38, 39, etc.). The control subsystems are preferably configured toreceive instructional commands or operation instructions such assoftware code from a respective grand master control 101, 102. Thecontrol subsystems 110, 113-119 preferably provide process and statusinformation to respective grand master controllers 101, 102.

More specifically, the grand master control 101 is coupled with aninterface module control 110 which may control each of the semiconductorworkpiece interface modules 38, 39. Further, grand master control 101 iscoupled with a conveyor control 113 for controlling operations of theworkpiece conveyor 60 and a plurality of processing module controls 114,115 corresponding to semiconductor workpiece processing modules 20, 22within the processing tool 10.

The control system 100 of the processing tool 10 according to thepresent invention may include additional grand master controllers 102 asshown in FIG. 14 for monitoring or operating additional subsystems, suchas additional workpiece processing modules via additional processingmodule control 119. Four control subsystems may be preferably coupledwith each grand master controller 101, 102. The grand master controllers101, 102 are preferably coupled together and each may transfer processdata to the other.

Each grand master controller 101, 102 receives and transmits data to therespective modular control subsystems 110-119. In a preferred embodimentof the control system 100, a bidirectional memory mapped device isprovided intermediate the grand master controller and each modularsubsystem connected thereto. In particular, memory mapped devices 160,161, 162 are provided intermediate the grand master controller 101 andmaster controllers 130, 131, 132 within respective interface modulecontrol 110, workpiece conveyor control 113 and processing modulecontrol 114.

Each memory mapped device 150, 160-162 within the control system 100 ispreferably a dual port RAM provided by Cypress for asynchronouoslystoring data. In particular, grand master controller 101 may write datato a memory location corresponding to master controller 130 and mastercontroller 130 may simultaneously read the data. Alternatively, grandmaster controller 101 may read data from mapped memory device beingwritten by the master controller 130. Utilizing memory mapped devices160-161 provides data transfer at processor speeds. Memory mapped device150 is preferably provided intermediate interface 30 and the grandmaster controllers 101, 102 for transferring data therebetween.

A user interface 30 is preferably coupled with each of the grand mastercontrollers 101, 102. The user interface 30 may be advantageouslymounted on the exterior of the processing tool 10 or at a remotelocation to provide an operator with processing and status informationof the processing tool 10. Additionally, an operator may input controlsequences and processing directives for the processing tool 10 via userinterface 30. The user interface 30 is preferably supported by a generalpurpose computer within the processing tool 10. The general purposecomputer preferably includes a 486 100 MHz processor, but otherprocessors may be utilized.

Master/Slave Configuration

Each modular control subsystem, including interface module control 110,workpiece conveyor control 113 and each processing module control114-119, is preferably configured in a master/slave arrangement. Themodular control subsystems 110, 113-119 are preferably housed within therespective module such as workpiece interface module 38, 39, workpiececonveyor 60, or each of the processing modules 20, 22, 24. The grandmaster controller 101 and corresponding master controllers 130, 131, 132coupled therewith are preferably embodied on a printed circuit board orISA board mounted within the general purpose computer supporting userinterface 30. Each grand master controller 101, 102 preferably includesa 68EC000 processor provided by Motorola and each master controller 130and slave controller within control system 100 preferably includes a80251 processor provided by Intel.

Each master controller 130, 131, 132 is coupled with its respectiveslave controllers via a data link 126, 127, 129 as shown in FIG. 16-FIG.18. Each data link 126, 127, 129 preferably comprises a optical datamedium such as Optilink provided by Hewlett Packard. However, data links126, 127, 129 may comprise alternate data transfer media.

Referring to FIG. 15, the master/slave control subsystem for theinterface module control 110 is illustrated. Each master and relatedslave configuration preferably corresponds to a single module (i.e.,interface, conveyor, processing) within the processing tool 10. However,one master may control or monitor a plurality of modules. Themaster/slave configuration depicted in FIG. 15 and corresponding to theinterface module control 110 may additionally apply to the other modularcontrol subsystems 113, 114, 115.

The grand master controller 101 is connected via memory mapped device160 to a master controller 130 within the corresponding interface modulecontrol 110. The master controller 130 is coupled with a plurality ofslave controllers 140, 141, 142. Sixteen slave controllers may bepreferably coupled with a single master controller 130-132 and eachslave controller may be configured to control and monitor a single motoror process component, or a plurality of motors and process components.

The control system 100 of the processing tool 10 preferably utilizesflash memory. More specifically, the operation instructions or programcode for operating each master controller 130-132 and slave controller140-147 within the control system 100 may be advantageously storedwithin the memory of the corresponding grand master controller 101, 102.Upon powering up, the grand master controller 101, 102 may poll thecorresponding master controllers 130-132 and download the appropriateoperation instruction program to operate each master controller 130-132.Similarly, each master controller 130-132 may poll respective slavecontrollers 140-147 for identification. Thereafter, the mastercontroller 130-132 may initiate downloading of the appropriate programfrom the grand master controller 101, 102 to the respective slavecontroller 140-147 via the master controller 130-132.

Each slave controller may be configured to control and monitor a singlemotor or a plurality of motors within a corresponding processing module19, interface module 38, 39 and workpiece conveyor 60. In addition, eachslave controller 140-147 may be configured to monitor and controlprocess components 184 within a respective module 19. Any one slavecontroller, such as slave controller 145 shown in FIG. 21, may beconfigured to control and/or monitor servo motors and process components184.

Each slave controller includes a slave processor which is coupled with aplurality of port interfaces. Each port interface may be utilized forcontrol and/or monitoring of servo motors and process components 184.For example, a port may be coupled with a servo controller card 176which is configured to operate a workpiece transfer unit 62, 64. Theslave processor 171 may operate the workpiece transfer unit 62, 64 viathe port and servo controller 176. More specifically, the slaveprocessor 171 may operate servo motors within the workpiece transferunit 62, 64 and monitor the state of the motor through the servocontroller 176.

Alternatively, different slave controllers 140, 141 may operatedifferent components within a single processing tool device, such asinterface module 38. More specifically, the interface module control 110and components of the interface module 38 are depicted in FIG. 16. Slavecontroller 140 may operate turnstile motor 185 and monitor the positionof the turnstile 40 via incremental turnstile encoder 190. Slavecontroller 140 is preferably coupled with the turnstile motor 185 andturnstile encoder 190 via a servo control card (shown in FIG. 19). Slavecontroller 141 may operate and monitor saddle 45 of the turnstile 40 bycontrolling saddle motor 186 and monitoring saddle encoder 191 via aservo control card.

A port of a slave processor may be coupled with an interface controllercard 180 for controlling and monitoring process components within arespective processing module 19. For example, a flow sensor 657 mayprovide flow information of the delivery of processing fluid to aprocessing bowl within the module. The interface controller 180 isconfigured to translate the data provided by the flow sensors 657 orother process components into a form which may be analyzed by thecorresponding slave processor 172. Further, the interface controller 180may operate a process component, such as a flow controller 658,responsive to commands from the corresponding slave processor 172.

One slave controller 140-147 may contain one or more servo controllerand one or more interface controller coupled with respective ports ofthe slave processor 170-172 for permitting control and monitorcapabilities of various component motors and processing components froma single slave controller.

Alternatively, a servo controller and interface controller may eachcontain an onboard processor for improving the speed of processing andoperation. Data provided by an encoder or process component to the servocontroller or interface controller may be immediately processed by theon board processor which may also control a respective servo motor orprocessing component responsive to the data. In such a configuration,the slave processor may transfer the data from the interface processoror servo controller processor to the respective master controller andgrand master controller.

Conveyor Control Subsystem

The conveyor control subsystem 113 for controlling and monitoring theoperation of the workpiece conveyor 60 and the workpiece transport units62, 64 therein is shown in FIG. 17. In general, a slave controller 143of conveyor control 113 is coupled with drive actuator 71 forcontrollably moving and monitoring a workpiece transport unit 62 alongthe guide 66. Further, slave controller 143 may operate transfer armassembly 86 of the workpiece transport unit 62 and the transferring ofsemiconductor workpieces thereby. Similarly, slave controller 144 may beconfigured to operate workpiece transport unit 64 and drive actuator 74.

The interfacing of slave controller 143 and light detector 91, driveactuator 71, linear encoder 196 and workpiece transport unit 62 is shownin detail in FIG. 20. The slave processor 171 of slave controller 143 ispreferably coupled with a servo controller 176. Slave processor 171 maycontrol the linear position of workpiece transport unit 62 by operatingdrive actuator 71 via servo controller 176. Light detector 91 mayprovide linear position information of the workpiece transport unit 62along guide 66. Additionally, a linear encoder 196 may also be utilizedfor precisely monitoring the position of workpiece transport unit 62along guide 66.

The conveyor slave processor 171 may also control and monitor theoperation of the transfer arm assembly 86 of the corresponding workpiecetransport unit 62. Specifically, the conveyor processor 171 may becoupled with a transfer arm motor 194 within shaft 83 for controllablyrotating the first and second arm extensions 87, 88. An incrementaltransfer arm rotation encoder 197 may be provided within the shaft 83 ofeach workpiece transport unit 62 for monitoring the rotation of transferarm assembly 86 and providing rotation data thereof to servo controller176 and slave processor 171.

Slave controller 143 may be advantageously coupled with transfer armelevation motor 195 within elevator 90 for controlling the elevationalposition of the transfer arm assembly 86. An incremental transfer armelevation encoder 198 may be provided within the transfer arm elevatorassembly 90 for monitoring the elevation of the transfer arm assembly86.

In addition, conveyor slave controller 143 may be coupled with an airsupply control valve actuator (not shown) via an interface controllerfor controlling a vacuum within wafer support 89 for selectivelysupporting a semiconductor workpiece thereon.

Absolute encoders 199 may be provided within the workpiece conveyor 60,interface modules 38, 39 and processing modules 19 to detect extremeconditions of operation and protect servo motors therein. For example,absolute encoder 199 may detect a condition where the transfer armassembly 86 has reached a maximum height and absolute encoder 199 mayturn off elevator 90 to protect transfer arm elevator motor 195.

Processing Module Control

The control system 100 preferably includes a processing module controlsubsystem 114-116 corresponding to each workpiece processing module 20,22, 24 within the processing tool 10 according to the present invention.The control system 100 may also include additional processing modulecontrol subsystem 119 for controlling and/or monitoring additionalworkpiece processing modules 19.

Respective processing module controls 114, 115, 116 may control andmonitor the transferring of semiconductor workpieces W between acorresponding workpiece holder 810 and workpiece transport unit 62, 64.Further, processing module controls 114, 115, 116 may advantageouslycontrol and/or monitor the processing of the semiconductor workpieces Wwithin each processing module 20, 22, 24.

Referring to FIG. 18, a single slave controller 147 may operate aplurality of workpiece holders 401 c-401 e within a processing module20. Alternatively, a single slave controller 145, 146 may operate andmonitor a single respective workpiece holder 401 a, 401 b. An additionalslave controller 148 may be utilized to operate and monitor all processcomponents 184 (i.e., flow sensors, valve actuators, heaters,temperature sensors) within a single processing module 19. Further, asshown in FIG. 21, a single slave controller 145 may operate and monitora workpiece holder 410 and process components 184.

In addition, a single slave controller 145-148 may be configured tooperate and monitor one or more workpiece holder 401 and processingcomponents 184. The interfacing of a slave controller 145 to both aworkpiece holder 401 and process components is shown in the controlsystem embodiment in FIG. 21. In particular, a servo controller 177 andinterface controller 180 may be coupled with respective ports connectedto slave processor 172 of slave controller 145.

Slave processor 172 may operate and monitor a plurality of workpieceholder components via servo controller 177. In particular, slaveprocessor 172 may operate lift motor 427 for raising operator arm 407about lift drive shaft 456. An incremental lift motion encoder 455 maybe provided within a workpiece holder 401 to provide rotationalinformation of lift arm 407 to the respective slave processor 172 or aprocessor within servo controller 177. Slave processor 172 may alsocontrol a rotate motor 428 within workpiece holder 401 for rotating aprocessing head 406 about shafts 429, 430 between a process position anda semiconductor workpiece transfer position. Incremental rotate encoder435 may provide rotational information regarding the processing head 406to the corresponding slave processor 172.

Spin motor 480 may also be controlled by a processor within servocontroller 177 or slave processor 172 for rotating the workpiece holder478 during processing of a semiconductor workpiece W held thereby. Anincremental spin encoder 498 is preferably provided to monitor the rateof revolutions of the workpiece holder 478 and supply the rateinformation to the slave processor 172.

Plating module control 114 advantageously operates the fingertips 414 ofthe workpiece holder 478 for grasping or releasing a semiconductorworkpiece. In particular, slave processor 172 may operate a valve viapneumatic valve actuator 201 for supplying air to pneumatic piston 502for actuating fingertips 414 for grasping a semiconductor workpiece. Theslave controller 145 within the plating module control 114 maythereafter operate the valve actuator 201 to remove the air supplythereby disengaging the fingertips 414 from the semiconductor workpiece.Slave processor 172 may also control the application of electricalcurrent through the finger assembly 824 during the processing of asemiconductor workpiece by operating relay 202.

The processing module controls 114, 115, 116 preferably operate andmonitor the processing of semiconductor workpieces within thecorresponding workpiece processing modules 20, 22, 24 viainstrumentation or process components 184.

Referring to FIG. 21, the control operation for the plating processingmodule 20 is described. Generally, slave processor 172 monitors and/orcontrols process components 184 via interface controller 180. Slaveprocessor 172 within the plating module control 114 operates pump 605 todraw processing solution from the process fluid reservoir 604 to thepump discharge filter 607. The processing fluid passes through thefilter, into supply manifold 652 and is delivered via bowl supply linesto a plurality of processing plating bowls wherein the semiconductorworkpieces are processed. Each bowl supply line preferably includes aflow sensor 657 coupled with the plating processing module control 114for providing flow information of the processing fluid thereto.Responsive to the flow information, the slave processor 172 may operatean actuator of flow controller 658 within each bowl supply line tocontrol the flow of processing fluid therethrough. Slave processor 172may also monitor and control a back pressure regulator 656 formaintaining a predetermined pressure level within the supply manifold652. The pressure regulator 656 may provide pressure information to theslave processor 172 within the plating processing control module 114.

Similarly, processing module control subsystems 115, 116 may beconfigured to control the processing of semiconductor workpieces withinthe corresponding prewet module 22 and resist module 24.

Interface Module Control

Each interface module control subsystem 110 preferably controls andmonitors the operation of workpiece interface modules 38, 39. Morespecifically, interface module control 110 controls and monitors theoperation of the workpiece cassette turnstiles 40, 41 and elevators 42,43 of respective semiconductor workpiece interface modules 38, 39 toexchange workpiece cassettes 16.

Slave processor 170 within slave controller 140 of interface modulecontrol 110 may operate and monitor the function of the interfacemodules 38, 39. In particular, slave processor 170 may operate doors 35,36 for providing access into the processing tool 10 via ports 32, 33.Alternatively, master control 100 may operate doors 35, 36.

Referring to FIG. 19, an embodiment of the interface module controlportion for controlling workpiece interface module 38 is discussed. Inparticular, the slave processor 170 is coupled with servo controller175. Either slave processor 170 or a processor on board servo controller175 may operate the components of interface module 38. In particular,slave processor 170 may control turnstile motor 185 for operating rotatefunctions of turnstile 40 moving workpiece cassettes 16 between a loadposition and a transfer position. Incremental turnstile encoder 190monitors the position of turnstile 40 and provides position data toslave processor 170. Alternatively, servo controller 175 may include aprocessor for reading information from turnstile encoder 190 andcontrolling turnstile motor 185 in response thereto. Servo controller175 may alert slave processor 170 once turnstile 40 has reaches adesired position.

Each workpiece cassette turnstile 40 includes a motor for controllingthe positioning of saddles 45, 46 connected thereto. The slave processor170 may control the position of saddles 45, 46 through operation of theappropriate saddle motor 186 to orient workpiece cassettes 16 attachedthereto in one of a vertical and horizontal orientation. Incrementalsaddle encoders 191 are preferably provided within each workpiececassette turnstile 40 for providing position information of the saddles45, 46 to the respective slave processor 170.

Either slave processor 170 or servo controller 175 may be configured tocontrol the operation of the workpiece cassette elevator 42 fortransferring a workpiece cassette 16 between either the exchangeposition and the extraction position. The slave processor 170 may becoupled with an elevator lift motor 187 and elevator rotation motor 188for controlling the elevation and rotation of elevator 42 and elevatorsupport 47. Incremental lift encoder 192 and incremental rotationencoder 193 may supply elevation and rotation information of theelevator 42 and support 47 to slave processor 170.

Absolute encoders 199 may be utilized to notify slave processor ofextreme conditions such as when elevator support 47 reaches a maximumheight. Elevator lift motor 187 may be shut down in response to thepresence of an extreme condition by absolute encoder 199.

Methods

Additional aspects of this invention include novel methods of handlingsemiconductor workpieces W within a semiconductor workpiece processingtool 10. The method of handling semiconductor workpieces within aprocessing tool 10 having at least one workpiece processing module 19and a workpiece conveyor 60 includes a step of receiving a workpiececassette 16 having a plurality of semiconductor workpieces W thereininto the workpiece processing tool 10. The method additionally includessteps of simultaneously moving a first and second workpiece transportunit 62, 64 along the workpiece conveyor 60 to simultaneously transportindividual semiconductor workpieces W between the workpiece cassettes 16and processing modules 19.

The workpiece cassette 16 may be preferably translated or otherwisereoriented between an approximately vertical orientation and anapproximately horizontal orientation within the workpiece processingtool 10. Specifically, each workpiece cassette 16 and the semiconductorworkpieces W therein are preferably oriented in a vertical positionduring the step of loading the workpiece cassette 16 into the processingtool 10 or removing a workpiece cassette 16 therefrom. The workpiececassettes 16 and semiconductor workpieces therein are preferablyoriented in a horizontal position during the step of extractingsemiconductor workpieces W from the workpiece cassette 16. Further, aplurality of workpiece cassettes 16 may be stored within the processingtool 10 to limit the exposure of the workspace 11 of the processing tool10 to the surrounding clean room environment.

The methods can also preferably provide for introducing unprocessedsemiconductor workpieces into a first interface module 38 for storage.Workpiece transport units 62, 64 may access the unprocessedsemiconductor workpieces within a workpiece cassette 16 held by thefirst interface module 38. Processed semiconductor workpieces arepreferably placed into workpiece cassettes 16 held within the outputprocessing module 39 for removal from the processing tool 10.

The present invention additionally provides for a method of handlingsemiconductor workpieces W within a processing tool 10 having aplurality of workpiece processing modules 19 adjacent opposing sides ofa workpiece conveyor 60. The processing modules are preferably alongboth sides and are accessible by transport units from either side ofconveyor 60. In particular, the method comprises the steps of receivinga workpiece cassette 16 into the processing tool 10 and storing theworkpiece cassette 16 therein. The semiconductor workpieces may beindividually transferred via the workpiece conveyor 60 to selectedworkpiece processing modules 19.

The method may include a translation step where the semiconductorworkpiece cassettes 16 are advantageously positioned in a verticalorientation for stability during the receiving step and in a horizontalorientation during an extraction step to facilitate access to thesemiconductor workpieces within a respective workpiece cassette 16. Theworkpiece transport units 62, 64 may access each workpiece processingmodule 19 adjacent opposing sides of the workpiece conveyor 60 totransfer the semiconductor workpieces therebetween. Preferably, eachworkpiece transport unit 62, 64 travels along paths defined by theworkpiece conveyor 60.

The method preferably provides for introducing unprocessed semiconductorworkpieces into a first interface module 38 for storage and placingprocessed semiconductor workpieces into workpiece cassettes 16 heldwithin the output processing module 39 for temporary storage and removalfrom the processing tool 10.

Workpiece Support

Turning now to FIG. 22, a semiconductor processing machine 400 havingtwo workpiece supports 401 is shown. Workpiece support 402 is shown in a“open” or “receive wafer” position in order to receive a workpiece orsemiconductor wafer for further processing. Workpiece support 403 isshown in a “closed” or “deployed” position wherein the semiconductorwafer has been received by the workpiece support and is being exposed tothe semiconductor manufacturing process in the semiconductormanufacturing chamber 404. FIG. 1 also shows an optional beam emitter 81for emitting a laser beam detected by robotic wafer conveyors toindicate position of the unit.

Turning now to FIG. 23, an enlarged view of the workpiece support 401 isshown. Workpiece support 401 advantageously includes operator base 405,a processing head 406, and an operator arm 407. Processing head 406preferably includes workpiece holder or wafer holder 408 and whichfurther includes fingers 409 for securely holding the workpiece duringfurther process and manufacturing steps. Workpiece holder 408 morepreferably spins about workpiece spin axis 410.

The processing head is advantageously rotatable about processing headpivot axis or, more briefly termed, process pivot axis 411. In thismanner, a workpiece (not shown) may be disposed between and grasped bythe fingers 409, at which point the processing head is preferablyrotated about process head pivot axis 411 to place the workpiece in aposition to be exposed to the manufacturing process.

In the preferred embodiment, operator arm 407 may be pivoted aboutoperator pivot axis 412. In this manner, the workpiece is advantageouslylowered into the process bowl (not shown) to accomplish a step in themanufacture of the semiconductor wafer.

Turning now to FIGS. 24-26, the sequence of placing a workpiece on theworkpiece support and exposing the workpiece to the semiconductormanufacturing process is shown. In FIG. 24, a workpiece W is shown asbeing held in place by fingertips 414 of fingers 409. Workpiece W isgrasped by fingertips 414 after being placed in position by robot orother means.

Once the workpiece W has been securely engaged by fingertips 414,processing head 406 can be rotated about process head pivot axis 411 asshown in FIG. 25. Process head 406 is preferably rotated about axis 411until workpiece W is at a desired angle, such as approximatelyhorizontal. The operator arm 407 is pivoted about operator arm pivotaxis 412 in a manner so as to coordinate the angular position ofprocessing head 406. In the closed position, the processing head isplaced against the rim of bowl 416 and the workpiece W is essentially ina horizontal plane. Once the workpiece W has been secured in thisposition, any of a series of various semiconductor manufacturing processsteps may be applied to the workpiece as it is exposed in the processingbowl 417.

Since the processing head 406 is engaged by the operator arm 407 on theleft and right side by the preferably horizontal axis 411 connecting thepivot points of processing head 406, a high degree of stability aboutthe horizontal plane is obtained. Further, since the operator arm 407 islikewise connected to the operator base 405 at left and right sidesalong the essentially horizontal line 412 connecting the pivot points ofthe operator arm, the workpiece support forms a structure having highrigidity in the horizontal plane parallel to and defined by axes 411 and412. Finally, since operator base 405 is securely attached to thesemiconductor process machine 400, rigidity about the spin axis 410 isalso achieved.

Similarly, since processing head 406 is nested within the fork or yokeshaped operator arm 407 having left and right forks 418 and 419,respectively, as shown in FIG. 23, motion due to cantilevering of theprocessing head is reduced as a result of the reduced moment arm definedby the line connecting pivot axes 411 and 412.

In a typical semiconductor manufacturing process, the workpiece holder408 will rotate the workpiece, having the process head 406 secured attwo points, that is, at the left and right forks 418 and 419,respectively, the vibration induced by the rotation of the workpieceholder 408 will be significantly reduced along the axis 411.

A more complete description of the components of the present inventionand their operation and interrelation follows.

Operator Base

Turning now to FIG. 30, operator base 405 is shown. The presentinvention advantageously includes an operator base 405 which forms anessentially yoke-shaped base having an operator base back portion 420,an operator base left yoke arm 421, and an operator base right yoke arm422. Yoke arms 421 and 422 are securely connected to the base of theyoke 420. In the preferred embodiment, the yoke arms are secured to theyoke base by the yoke arm fasteners 423. The yoke arm base in turn isadvantageously connected to the semiconductor process machine 400 asshown in FIG. 22.

The upper portions of the yoke arm advantageously include receptaclesfor housing the operator arm bearings 424 which are used to support thepivot shafts of the operator arm 425, described more fully below.

Operator Arm

Still viewing FIG. 30, the present invention advantageously includes anoperator arm 407. As described previously, operator arm 407 preferablypivots about the operator arm pivot axis 412 which connects the centerline defined by the centers of operator arm pivot bearings 424.

Operator arm or pivot arm 407 is advantageously constructed in such amanner to reduce mass cantilevered about operator arm pivot axis 412.This allows for quicker and more accurate positioning of the pivot armas it is moved about pivot arm axis 412.

The left fork of the pivot arm 418, shown more clearly in FIG. 32,houses the mechanism for causing the pivot arm to lift or rotate aboutpivot arm pivot axis 412. Pivot arm right fork 419, shown more clearlyin FIG. 31, houses the mechanism for causing the processing head 406(not shown) to rotate about the process head pivot axis 411.

The process arm rear cavity 426, shown in FIG. 30, houses the lift motor452 for causing the operator arm 407 to rotate about pivot arm axis 412.Process arm rear cavity 426 also houses rotate motor 428 which is usedto cause the processing head 406 to rotate about the processing headpivot axis 411. The rotate motor 428 may more generally be described asa processing head pivot or rotate drive. Processing head 406 is mountedto operator arm 407 at processing head left pivot shaft 429 andprocessing head right pivot shaft 430.

Operator arm 407 is securely attached to left yoke arm 421 and rightyoke arm 422 by operator arm pivot shafts 425 and operator arm pivotbearings 424, the right of which such bearing shaft and bearings areshown in FIG. 30.

Operator Arm-Processing Head Rotate Mechanism

Turning now to FIG. 34, a sectional plan view of the right rear cornerof operator arm 407 is shown. The right rear section of operator arm 407advantageously contains the rotate mechanism which is used to rotateprocessing head 406 about processing head pivot shafts 430 and 429.Processing head rotate mechanism 431 preferably consists of rotate motor428 which drives rotate shaft 432, more generally described as aprocessing head drive shaft. Rotate shaft 432 is inserted within rotatepulley 425 which also functions as the operator arm pivot shaft. Asdescribed previously, the operator arm pivot shaft/lift pulley issupported in operator arm pivot bearings 424, which are themselvessupported in operator base yoke arm 422. Rotate shaft 432 is securedwithin left pulley 424 by securing collar 433. Securing collar 433secures rotate pulley 425 to rotate shaft 432 in a secure manner so asto assure a positive connection between rotate motor 428 and rotatepulley 425. An inner cover 584 is also provided.

Rotate motor 428 is disposed within process arm rear cavity 426 and issupported by rotate motor support 434. Rotate motor 428 preferably is aservo allowing for accurate control of speed and acceleration of themotor. Servo motor 428 is advantageously connected to rotate encoder 435which is positioned on one end of rotate motor 428. Rotate encoder 435,more generally described as processing head encoder, allows for accuratemeasurement of the number of rotations of rotate motor 428, as well asthe position, speed, and acceleration of the rotate shaft 432. Theinformation from the rotate encoder may be used in a rotate circuitwhich may then be used to control the rotate motor when the rotate motoris a servo. This information is useful in obtaining the position andrate of travel of the processing head, as well as controlling the finalend point positions of the processing head as it is rotated aboutprocess head rotate axis 411.

The relationship between the rotate motor rotations, as measured byrotate encoder 435, may easily be determined once the diameters of therotate pulley 425 and the processing head pulley 438 are known. Thesediameters can be used to determine the ratio of rotate motor relationsto processing head rotations. This may be accomplished by amicroprocessor, as well as other means.

Rotate pulley 425 is further supported within operator arm 407 by rotatepulley inboard bearing 436 which is disposed about an extended flange onthe rotate pulley 425. Rotate pulley inboard bearing 436 is secured bythe body of the operator arm 407, as shown in FIG. 34.

Rotate pulley 425 advantageously drives rotate belt 437, more generallydescribed as a flexible power transmission coupling. Referring now toFIG. 31, rotate belt 437 is shown in the side view of the right arm 419of the operator arm 407. Rotate belt 437 is preferably a toothed timingbelt to ensure positive engagement with the processing head drive wheel,more particularly described herein as the processing head pulley 438,(not shown in this view). In order to accommodate the toothed timingbelt 437, both the rotate pulley 425 and the processing head pulley 438are advantageously provided with gear teeth to match the tooth patternof the timing belt to assure positive engagement of the pulleys with therotate belt.

Rotate mechanism 431 is preferably provided with rotate belt tensioner439, useful for adjusting the belt to take up slack as the belt maystretch during use, and to allow for adjustment of the belt to assurepositive engagement with both the rotate pulley and the processing headpulley. Rotate belt tensioner 439 adjusts the tension of rotate belt 437by increasing the length of the belt path between rotate pulley 425 andprocessing head pulley 438, thereby accommodating any excess lengths inthe belt. Inversely, the length of the belt path may also be shortenedby adjusting rotate belt tensioner 439 so as to create a more linearpath in the upper portion of rotate belt 437. The tensioner 439 isadjusted by rotating it about tensioner hub 468 and securing it in a newposition.

Turning now to FIG. 34, processing head pulley 438 is mounted toprocessing head rotate shaft 430 in a secured manner so that rotation ofprocessing head pulley 438 will cause processing head rotate shaft 430to rotate. Processing head shaft 430 is mounted to operator arm rightfork 419 by processing head shaft bearing 440, which in turn is securedin the frame of the right fork 419 by processing head rotate bearing469. In a like manner, processing head shaft 429 is mounted in operatorarm left fork 418 by processing head shaft bearing 441, as shown in FIG.30.

Processing head pivot shafts 430 and 429 are advantageously hollowshafts. This feature is useful in allowing electrical, optical,pneumatic, and other signal and supply services to be provided to theprocessing head. Service lines such as those just described which arerouted through the hollow portions of processing head pivot shafts 429and 430 are held in place in the operator arms by cable brackets 442 and443. Cable brackets 442 and 443 serve a dual purpose. First, routing theservice lines away from operating components within the operator armleft and right forks. Second, cable brackets 442 and 443 serve a usefulfunction in isolating forces imparted to the service cables by therotating action of processing head 406 as it rotates about processinghead pivot shafts 429 and 430. This rotating of the processing head 406has the consequence that the service cables are twisted within the pivotshafts as a result of the rotation, thereby imparting forces to thecables. These forces are preferably isolated to a particular area so asto minimize the effects of the forces on the cables. The cable brackets442 and 443 achieve this isolating effect.

The process head rotate mechanism 431, shown in FIG. 34, is alsoadvantageously provided with a rotate overtravel protect 444, whichfunctions as a rotate switch. Rotate overtravel protect 444 preferablyacts as a secondary system to the rotate encoder 435 should the controlsystem fail for some reason to stop servo 428 in accordance with apredetermined position, as would be established by rotate encoder 435.Turning to FIG. 34, the rotate overtravel protect 444 is shown in planview. The rotate overtravel protect preferably consists of rotateoptical switches 445 and 446, which are configured to correspond to theextreme (beginning and end point) portions of the processing head, aswell as the primary switch component which preferably is a rotate flag447. Rotate flag 447 is securely attached to processing head pulley 438such that when processing head shaft 430 (and consequently processinghead 406) are rotated by virtue of drive forces imparted to theprocessing head pulley 425 by the rotate belt 437, the rotate flag 447will rotate thereby tracking the rotate motion of processing head 406.Rotate optical switches 445 and 446 are positioned such that rotate flag447 may pass within the optical path generated by each optical switch,thereby generating a switch signal. The switch signal is used to controlan event such as stopping rotate motor 428. Rotate optical switch 445will guard against overtravel of processing head 406 in one direction,while rotate optical switch 446 will provide against overtravel of theprocessing head 406 in the opposite direction.

Operator Arm-Lift Mechanism

Operator arm 407 is also advantageously provided with an operator armlift mechanism 448 which is useful for causing the operator arm to lift,that is, to pivot or rotate about operator arm pivot axis 412. Turningto FIG. 35, the operator arm lift mechanism 448 is shown in thesectional plan view of the right rear corner of operator arm 407.

Operator arm lift mechanism 448 is advantageously driven by lift motor452. Lift motor 452 may be more generally described as an operator armdrive or operator arm pivot drive. Lift motor 452 is preferably a servomotor and is more preferably provided with an operator encoder, morespecifically described as lift motor encoder 456. When lift motor 452 isa servo motor coupled with lift encoder 456, information regarding thespeed and absolute rotational position of the lift motor shaft 454 maybe known from the lift encoder signal. Additionally, by virtue of beinga servo mechanism, the angular speed and acceleration of lift motor 452may be easily controlled by use of the lift signal by an electricalcircuit. Such a lift circuit may be configured to generate desired liftcharacteristics (speed, angle, acceleration, etc.). FIG. 14 shows thatthe lift operator may also include a brake 455 which is used to safelystop the arm if power fails.

Lift motor 452 drives lift motor shaft 454 which in turn drives liftgear drive 453. Lift gear drive 453 is a gear reduction drive to producea reduced number of revolutions at lift drive shaft 456 as the functionof input revolutions from lift motor shaft 454.

Lift drive gear shaft 456 is secured to lift anchor 451 which is moreclearly shown in FIG. 32. Lift anchor 451 is preferably shaped to haveat least one flat side for positively engaging lift bushing 449. Liftanchor 451 is secured to lift drive shaft 456 by anchor plate 458 andanchor fasteners 457. In this manner, when lift drive shaft 456 isrotated, it will positively engage lift bushing 449. Returning to FIG.35, it is seen that lift bushing 449 is mounted in operator left yokearm 421, and is thus fixed with respect to operator base 405. Liftbearing 450 is disposed about the lift bushing shank and is supported inoperator arm 407 by lift bearing support 460 which is a bushingconfigured to receive lift bearing 450 on a first end and to supportlift gear drive 453 on a second end. Lift bearing support 460 is furthersupported within operator arm 407 by operator arm frame 461. The liftarm is thus free to pivot about lift bushing 449 by virtue of liftbearing 450.

In operation, as lift motor 452 causes lift gear drive 453 to producerotations at gear drive shaft 456, lift anchor 451 is forced againstlift bushing 449 which is securely positioned within right operator yokearm 421. The reactive force against the lift anchor 451 will cause liftbearing support 460 to rotate relative to lift bushing 449. Since liftbushing 449 is fixed in operator base 405, and since operator base 405is fixed to processing machine 400, rotation of lift bearing support 460will cause lift arm 407 to pivot about operator arm pivot axis 412,thereby moving the processing head 406. It is advantageous to considerthe gear drive shaft (or “operator arm shaft”) as being fixed withrespect to operator base 405 when envisioning the operation of the liftmechanism.

Operator lift mechanism 448 is also advantageously provided with a liftovertravel protect 462 or lift switch. The lift rotate protect operatesin a manner similar to that described for the rotate overtravel protect444 described above. Turning now to FIG. 32, a left side view of theoperator arm 407 is shown which shows the lift overtravel protect indetail.

The lift overtravel protect preferably includes a lift optical switchlow 463 and a lift optical switch high 464. Other types of limitswitches can also be used. The switch high 464 and switch low 463correspond to beginning and endpoint travel of lift arm 407. The primarylift switch component is lift flag 465, which is firmly attached to leftoperator base yoke arm 421. The lift optical switches are preferablymounted to the movable operator arm 407. As operator arm 407 travels inan upward direction in pivoting about operator arm pivot axis 412, liftoptical switch high 464 will approach the lift flag 465. Should the liftmotor encoder 455 fail to stop the lift motor 454 as desired, the liftflag 465 will break the optical path of the lift optical switch high 464thus producing a signal which can be used to stop the lift motor. Inlike manner, when the operator arm 407 is being lowered by rotating itin a clockwise direction about the operator arm pivot axis 412, as shownin FIG. 32, overtravel of operator arm 407 will cause lift opticalswitch low 463 to have its optical path interrupted by lift flag 465,thus producing a signal which may be used to stop lift motor 452. As isshown in FIG. 32, lift flag 465 is mounted to left operator base yokearm 421 with slotted lift flag mounting slots 467 and removable liftflag fasteners 466. Such an arrangement allows for the lift flag to beadjusted so that the lift overtravel protect system only becomes activeafter the lift arm 407 has traveled beyond a preferred point.

Processing Head

Turning now to FIG. 27, a front elevation schematic view of theprocessing head 406 is shown. Processing head 406 is described in moredetail in FIGS. 28 and 29. Turning now to FIG. 28, a sectional view ofthe left front side of processing head 406 is shown. Processing head 406advantageously includes a processing head housing 470 and frame 582.Processing head 406 is preferably round in shape in plan view allowingit to easily pivot about process head pivot axis 411 with nointerference from operator arm 407, as demonstrated in FIGS. 24-26.Returning to FIG. 28, processing head housing 470 more preferably hascircumferential grooves 471 which are formed into the side of processhead housing 470. Circumferential grooves 471 have a functional benefitof increasing heat dissipation from processing head 406.

The sides of processing head housing 470 are advantageously providedwith rotate shaft openings 474 and 475 for receiving respectively leftand right processing head pivot shafts 429 and 430. Processing headpivot shafts 429 and 430 are secured to the processing head 406 byrespective left and right processing head mounts 472 and 473. Processinghead mounts 472 and 473 are affirmative connected to processing headframe 582 which also supports processing head door 476 which is itselfsecurely fastened to processing head housing 470. Consequently,processing head pivot shafts 429 and 430 are fixed with respect toprocessing head 407 and may therefore rotate or pivot with respect tooperator arm 407. The details of how processing head pivot shafts 429and 430 are received within operator arm 407 were discussed supra.

Processing head housing 470 forms a processing head void 477 which isused to house additional processing head components such as the spinmotor, the pneumatic finger actuators, and service lines, all discussedmore fully below.

The processing head also advantageously includes a workpiece holder andfingers for holding a workpiece, as is also more fully described below.

Processing Head Spin Motor

In a large number of semiconductor manufacturing processes, is desirableto spin the semiconductor wafer or workpiece during the process, forexample to assure even distribution of applied process fluids across theface of the semiconductor wafer, or to aid drying of the wafer after awet chemistry process. It is therefore desirable to be able to rotatethe semiconductor workpiece while it is held by the processing head.

The semiconductor workpiece is held during the process by workpieceholder 478 described more fully below. In order to spin workpiece holder478 relative to processing head 406 about spin axis 479, an electric,pneumatic, or other type of spin motor or workpiece spin drive isadvantageously provided.

Turning to FIG. 29, spin motor 480 has armatures 526 which drive spinmotor shaft 483 in rotational movement to spin workpiece holder 478.Spin motor 480 is supported by bottom motor bearing 492 in bottom motorhousing 482. Bottom motor housing 482 is secured to processing head 406by door 476. Spin motor 480 is thus free to rotate relative toprocessing head housing 470 and door 476. Spin motor 480 is preferablyadditionally held in place by top motor housing 481 which rests onprocessing head door 476. Spin motor 480 is rotationally isolated fromtop motor housing 481 by top motor bearing 493, which is disposedbetween the spin motor shaft 483 and top motor housing 481.

The spin motor is preferably an electric motor which is provided with anelectrical supply source through pivot shaft 429 and/or 430. Spin motor480 will drive spin motor shaft 483 about spin axis 479.

To secure workpiece holder rotor 484 to spin motor shaft 483, workpieceholder rotor 484 is preferably provided with a rotor hub 485. Rotor hub485 defines a rotor hub recess 486 which receives a flared end ofworkpiece holder shaft 491. The flared end 487 of workpiece holder shaft491 is secured within the rotor hub recess 486 by workpiece shaftsnap-ring 488 which fits within rotor recess groove 489 above the flaredportion 487 of workpiece holder shaft 491.

The workpiece holder shaft 491 is fitted inside of spin motor shaft 483and protrudes from the top of the spin motor shaft. The top of workpieceholder shaft 491 is threaded to receive thin nut 527 (see FIG. 28). Thinnut 527 is tightened against optical tachometer 499 (describe more fullybelow). Optical tachometer 499 is securely attached to spin motor shaft483 such that as the spin motor 480 rotationally drives the spin motorshaft 483, the workpiece holder shaft 491 is also driven.

Workpiece holders may be easily changed out to accommodate variousconfigurations which may be required for the various processesencountered in manufacturing of the semiconductors. This is accomplishedby removing spin encoder 498 (described below), and then thin nut 527.Once the thin nut has been removed the workpiece holder 478 will dropaway from the processing head 406.

The processing head is also advantageously provided with a spin encoder498, more generally described as a workpiece holder encoder, and anoptical tachometer 499. As shown in FIG. 28, spin encoder 498 is mountedto top motor housing 481 by encoder support 528 so as to remainstationary with respect to the processing head 406. Optical tachometer499 is mounted on spin motor shaft 483 so as to rotate with the motor480. When operated in conjunction, the spin encoder 498 and opticaltachometer 499 allow the speed, acceleration, and precise rotationalposition of the spin motor shaft (and therefore the workpiece holder478) to be known. In this manner, and when spin motor 480 is provided asa servo motor, a high degree of control over the spin rate,acceleration, and rotational angular position of the workpiece withrespect to the process head 407 may be obtained.

In one application of the present invention the workpiece support isused to support a semiconductor workpiece in an electroplating process.To accomplish the electroplating an electric current is provided to theworkpiece through an alternate embodiment of the fingers (described morefully below). To provide electric current to the finger, conductivewires are run from the tops of the fingers inside of the workpieceholder 478 through the electrode wire holes 525 in the flared lower partof workpiece holder shaft 491. The electrode wires are provided electriccurrent from electrical lines run through processing pivot shaft 429and/or 430.

The electrical line run through pivot shaft 430/429 will by nature bestationary with respect to processing head housing 470. However, sincethe workpiece holder rotor is intended to be capable of rotation duringthe electroplating process, the wires passing into workpiece supportshaft 491 through electrode wire holes 525 may rotate with respect toprocessing head housing 470. Since the rotating electrode wires withinworkpiece shaft 491 and the stationary electrical supply lines runthrough pivot shaft 430/429 must be in electrical communication, therotational/stationary problem must be overcome. In the preferredembodiment, this is accomplished by use of electrical slip ring 494.

Electrical slip ring 494, shown in FIG. 28, has a lower wire junction529 for receiving the conductive ends of the electrical wires passinginto workpiece holder shaft 491 by electrode wire holes 525. Lower wirejunction 529 is held in place within workpiece holder shaft 491 byinsulating cylindrical collar 497 and thus rotates with spin motor shaft483. The electrode wires terminate in a single electrical contact 531 atthe top of the lower wire junction 529. Electrical slip ring 494 furtherhas a contact pad 530 which is suspended within the top of workpieceholder shaft 491. Contact pad 530 is mechanically fastened to spinencoder 498, which, as described previously, remains stationary withrespect to processing head housing 470. The stationary to rotationaltransition is made at the tip of contact pad 530, which is in contactwith the rotating electrical contact 531. Contact pad 530 iselectrically conductive and is in electrical communication withelectrical contact 531. In the preferred embodiment, contact pad 530 ismade of copper-beryllium. A wire 585 carries current to fingerassemblies when current supply is needed, such as on the alternativeembodiment described below.

Processing Head Finger Actuators

Workpiece holder 478, described more fully below, advantageouslyincludes fingers for holding the workpiece W in the workpiece holder, asshown in FIGS. 28 and 29. Since the workpiece holder 478 may be removedas described above, it is possible to replace one style of workpieceholder with another. Since a variety of workpiece holders with a varietyof fingers for holding the workpiece is possible, it is desirable tohave a finger actuator mechanism disposed within processing head 407which is compatible with any given finger arrangement. The invention istherefore advantageously provided with a finger actuator mechanism.

Turning to FIG. 28, a finger actuator mechanism 500 is shown. Fingeractuator mechanism 500 is preferably a pneumatically operated mechanism.A pneumatic cylinder is formed by a cavity 501 within top motor housing481. Pneumatic piston 502 is disposed within cavity 501. Pneumaticpiston 502 is biased in an upward position within cavity 501 by actuatorspring 505. Actuator spring 505 is confined within cavity 501 by cavityend cap 507, which is itself constrained by retaining ring 508.Pneumatic fluid is provided to the top of pneumatic piston 502 viapneumatic inlet 503. Pneumatic fluid is provided to pneumatic inlet 503by pneumatic supply line 504 which is routed through processing headpivot shaft 429 and hence through the left fork 418 of the operator arm407. Turning to FIG. 29, it can be seen that a second pneumatic cylinderwhich is identical to the pneumatic cylinder just described is alsoprovided.

Pneumatic piston 502 is attached to actuator plate 509 by actuator plateconnect screw 510. Wave springs 529 provide flexibility to theconnecting at screws 510. Actuator plate 509 is preferably an annularplate concentric with the spin motor 580 and disposed about the bottommotor housing 482, and is symmetrical about spin axis 479. Actuatorplate 509 is secured against pneumatic piston 502 by bushing 512 whichis disposed in pneumatic piston recess 511 about pneumatic piston 502.Bushing 512 acts as a support for wave springs 529 to allow a slighttilting of the actuator plate 509. Such an arrangement is beneficial forproviding equal action against the finger actuator contracts 513 aboutthe entire actuator plate or ring 509.

When pneumatic fluid is provided to the space above the pneumatic piston502, the pneumatic piston 502 travels in a downward directioncompressing actuator spring 505. As pneumatic piston 502 travelsdownward, actuator plate 509 is likewise pushed downward by flexiblebushing 512. Actuator plate 509 will contact finger actuator contacts513 causing the fingers to operate as more fully described below.

Actuator seals 506 are provided to prevent pneumatic gas from bypassingthe top of the pneumatic piston 502 and entering the area occupied byactuator spring 505.

Processing Head Workpiece Holder

Workpiece holder 478 is used to hold the workpiece W, which is typicallya semiconductor wafer, in position during the semiconductormanufacturing process.

Turning now to FIG. 29, a finger 409 is shown in cross section. Finger409 advantageously includes a finger actuator contact 513 which iscontacted by actuator plate 509, as described above. Finger actuatorcontact 513 is connected to finger actuator lever 514 (more generally,“finger extension”) which is cantilevered from and connected to thefinger stem 515. Finger stem 515 is inserted into finger actuator lever514. Disposed about the portion of the finger actuator lever whichencompasses and secures finger stem 515 is finger diaphragm 519. Fingerdiaphragm 519 is preferably made of a flexible material such asTetrafluoroethylene, also known as Teflon® (registered trademark of E.I.DuPont de Nemours Company). Finger 409 is mounted to workpiece holderrotor 484 using finger diaphragm 519. Finger diaphragm 519 is insertedinto the finger opening 521 in rotor 484. The finger diaphragm 519 isinserted into the rotor from the side opposite that to which theworkpiece will be presented. Finger diaphragm 519 is secured to rotor484 against rotor diaphragm lip 523. Forces are intentionally impartedas a result of contact between the actuator plate 509 and the fingeractuator contact 513 when the finger actuator mechanism 500 is actuated.

Finger actuator lever 514 is advantageously biased in a horizontalposition by finger spring 520 which acts on finger actuator tab 522which in turn is connected to finger actuator lever 514. Finger spring520 is preferably a torsion spring secured to the workpiece holder rotor484.

Finger stem 515 is also preferably provided with finger collar or nut517 which holds the finger stem 515 against shoulder 518. Finger collar517 threads or otherwise securely fits over the lower end of fingeractuator lever 514. Below the finger collar 517, finger stem 515 extendsfor a short distance and terminates in fingertip 414. Fingertip 414contains a slight groove or notch which is beneficially shaped toreceive the edge of the workpiece W.

In actuation, finger actuator plate 509 is pushed downward by fingeractuator mechanism 500. Finger actuator plate 509 continues its downwardtravel contacting finger actuator contacts 513. As actuator plate 509continues its downward travel, finger actuator contacts are pushed in adownward direction. As a result of the downward direction, the fingeractuator levers 514 are caused to pivot.

In the preferred embodiment, a plurality of fingers are used to hold theworkpiece. In one example, six fingers were used. Once the actuatorplate 509 has traveled its full extent, the finger stems 515 will betilted away from the spin axis 479. The circumference described by thefingertips in this spread-apart position should be greater than thecircumference of the workpiece W. Once a workpiece W has been positionedproximate to the fingertips, the pneumatic pressure is relieved on thefinger actuator and the actuator spring 505 causes the pneumatic piston502 to return to the top of the cavity 501. In so doing, the actuatorplate 509 is retracted and the finger actuator levers are returned totheir initial position by virtue of finger springs 520.

Semiconductor Workpiece Holder—Electroplating Embodiment

FIG. 36 is a side elevational view of a semiconductor workpiece holder810 constructed according to a preferred aspect of the invention.

Workpiece holder 810 is used for processing a semiconductor workpiecesuch as a semiconductor wafer shown in phantom at W. One preferred typeof processing undertaken with workpiece holder 810 is a workpieceelectroplating process in which a semiconductor workpiece is held byworkpiece holder 810 and an electrical potential is applied to theworkpiece to enable plating material to be plated thereon. Such can be,and preferably is accomplished utilizing a processing enclosure orchamber which includes a bottom half or bowl 811 shown in phantom linesin FIG. 1. Bottom half 811 together with workpiece holder 810 forms asealed, protected chamber for semiconductor workpiece processing.Accordingly, preferred reactants can be introduced into the chamber forfurther processing. Another preferred aspect of workpiece holder 810 isthat such moves, rotates or otherwise spins the held workpiece duringprocessing as will be described in more detail below.

Processing Head and Processing Head Operator

Turning now to FIG. 36, semiconductor workpiece holder 810 includes aworkpiece support 812. Workpiece support 812 advantageously supports aworkpiece during processing. Workpiece support 812 includes a processinghead or spin head assembly 814. Workpiece support 812 also includes ahead operator or lift/rotate assembly 816. Spin head assembly 814 isoperatively coupled with lift/rotate assembly 816. Spin head assembly814 advantageously enables a held workpiece to be spun or moved about adefined axis during processing. Such enhances conformal coverage of thepreferred plating material over the held workpiece. Lift/rotate assembly816 advantageously lifts spin head assembly 814 out of engagement withthe bottom half 811 of the enclosure in which the preferred processingtakes place. Such lifting is preferably about an axis x₁. Once solifted, lift/rotate assembly 816 also rotates the spin head and heldworkpiece about an axis x₂ so that the workpiece can be presentedface-up and easily removed from workpiece support 812. In theillustrated and preferred embodiment, such rotation is about 180° fromthe disposition shown in FIG. 36. Advantageously, a new workpiece can befixed or otherwise attached to the workpiece holder for furtherprocessing as described in detail below.

The workpiece can be removed from or fixed to workpiece holder 810automatically by means of a robotically controlled arm. Alternatively,the workpiece can be manually removed from or fixed to workpiece holder810. Additionally, more than one workpiece holder can be provided tosupport processing of multiple semiconductor workpieces. Other means ofremoving and fixing a semiconductor workpiece are possible.

FIG. 37 is a front sectional view of the FIG. 36 semiconductor workpieceholder. As shown, workpiece support 812 includes a motor 818 which isoperatively coupled with a rotor 820. Rotor 820 is advantageouslymounted for rotation about a rotor spin axis 822 and serves as a stagingplatform upon which at least one finger assembly 824 is mounted.Preferably, more than one finger assembly is mounted on rotor 820, andeven more preferably, four or more such finger assemblies are mountedthereon and described in detail below although only two are shown inFIG. 37. The preferred finger assemblies are instrumental in fixing orotherwise holding a semiconductor workpiece on semiconductor workpieceholder 810. Each finger assembly is advantageously operatively connectedor associated with a actuator 825. The actuator is preferably apneumatic linkage which serves to assist in moving the finger assembliesbetween a disengaged position in which a workpiece may be removed fromor added to the workpiece holding, and an engaged position in which theworkpiece is fixed upon the workpiece holder for processing. Such isdescribed in more detail below.

FIG. 38 is a top or plan view of rotor 820 which is effectively takenalong line 3-3 in FIG. 37. FIG. 37 shows the preferred four fingerassemblies 824. As shown, rotor 820 is generally circular and resemblesfrom the top a spoked wheel with a nearly continuous bottom surface.Rotor 820 includes a rotor center piece 826 at the center of which liesrotor axis 822. A plurality of struts or spokes 828 are joined orconnected to rotor center 826 and extend outwardly to join with andsupport a rotor perimeter piece 830. Advantageously, four of spokes 828support respective preferred finger assemblies 824. Finger assemblies824 are advantageously positioned to engage a semiconductor workpiece,such as a wafer W which is shown in phantom lines in the position suchwould occupy during processing. When a workpiece is so engaged, it isfixedly held in place relative to the rotor so that processing can beeffected. Such processing can include exposing the workpiece toprocessing conditions which are effective to form a layer of material onone or more surfaces or potions of a wafer or other workpiece. Suchprocessing can also include moving the workpiece within a processingenvironment to enhance or improve conformal coverage of a layeringmaterial. Such processing can, and preferably does include exposing theworkpiece to processing conditions which are effective to form anelectroplated layer on or over the workpiece.

Finger Assembly

Referring now to FIGS. 39-41, various views of a preferred fingerassembly are shown. The preferred individual finger assemblies areconstructed in accordance with the description below. FIG. 39 is anisolated side sectional view of a finger assembly constructed inaccordance with a preferred aspect of the invention. FIG. 40 is a sideelevational view of the finger assembly turned 90° from the view of FIG.39. FIG. 41 is a fragmentary cross-sectional enlarged view of a fingerassembly and associated rotor structure. The finger assembly as setforth in FIGS. 39 and 40 is shown in the relative position such as itwould occupy when processing head or spin head assembly 814 (FIGS. 36and 37) is moved or rotated by head operator or lift/rotate assembly 816into a position for receiving a semiconductor workpiece. The fingerassembly is shown in FIGS. 39 and 41 in an orientation of about 180°from the position shown in FIG. 41. This typically varies because spinhead assembly 814 is rotated 180° from the position shown in FIGS. 36and 37 in order to receive a semiconductor workpiece. Accordingly,finger assemblies 824 would be so rotated. Lesser degrees of rotationare possible.

Finger assembly 824 includes a finger assembly frame 832. Preferably,finger assembly frame 832 is provided in the form of a sealed contactsleeve which includes an angled slot 832 a, only a portion of which isshown in FIG. 40. Angled slot 832 a advantageously enables the fingerassembly to be moved, preferably pneumatically, both longitudinally androtationally as will be explained below. Such preferred movement enablesa semiconductor workpiece to be engaged, electrically contacted, andprocessed in accordance with the invention.

Finger assembly frame 832 includes a finger assembly frame outer flange834 which, as shown in FIG. 41, engages an inner drive plate portion 836of rotor 820. Such engagement advantageously fixes or seats fingerassembly frame 832 relative to rotor 820. Such, in turn, enables thefinger assembly, or a portion thereof, to be moved relative to the rotorfor engaging the semiconductor workpiece.

Finger Assembly Drive System

Referring to FIGS. 37 and 39-41, the finger assembly includes a fingerassembly drive system which is utilized to move the finger assemblybetween engaged and disengaged positions. The finger assembly drivesystem includes a bearing 838 and a collet 840 operatively adjacent thebearing. Bearing 838 includes a bearing receptacle 839 for receiving apneumatically driven source, a fragmented portion of which is showndirectly above the receptacle in FIG. 41. The pneumatically drivensource serves to longitudinally reciprocate and rotate collet 840, andhence a preferred portion of finger assembly 824. A preferredpneumatically driven source is described below in more detail inconnection with the preferred longitudinal and rotational movementeffectuated thereby. Such longitudinal reciprocation is affected by abiasing mechanism in the form of a spring 842 which is operativelymounted between finger assembly frame 832 and a spring seat 844. Theconstruction develop a bias between finger assembly frame 832 and springseat 844 to bias the finger into engagement against a wafer.Advantageously, the cooperation between the above mentionedpneumatically driven source as affected by the biasing mechanism of thefinger assembly drive system, enable collet 840 to be longitudinallyreciprocated in both extending and retracting modes of movement. Assuch, finger assembly 824 includes a biased portion which is biasedtoward a first position and which is movable to a second position awayfrom the first position. Other manners of longitudinally reciprocatingthe finger assembly are possible.

Finger Assembly Electrical System

Referring to FIGS. 37 and 40, the finger assembly preferably includes afinger assembly electrical system which is utilized to effectuate anelectrical bias to a held workpiece and supply electrical currentrelative thereto. The finger assembly electrical system includes a pinconnector 846 and a finger 848. Pin connector 846 advantageouslyprovides an electrical connection to a power source (not shown) via wire585 and associate slip ring mechanism, described above in connectionwith FIG. 28 and other Figs. This is for delivering an electrical biasand current to an electrode which is described below. Pin connector 846also rides within angled slot 832 a thereby mechanically defining thelimits to which the finger assembly may be both longitudinally androtationally moved.

Finger 848 is advantageously fixed or secured to or within collet 840 bya nut 850 which threadably engages a distal end portion of collet 840 asshown best in FIG. 39. An anti-rotation pin 852 advantageously securesfinger 848 within collet 840 and prevents relative rotationtherebetween. Electrical current is conducted from connector 846 throughcollet 840 to finger 860, all of which are conductive, such as fromstainless steel. The finger and collet cain be coated with a suitabledielectric coating 856, such as TEFLON or others. The collet 840 andfinger member 860 are in one form of the invention made hollow andtubular to conduct a purge gas therethrough.

Finger assembly 824 may also optionally include a distal tip or fingertip 854. Tip 854 may also have a purge gas passage formed therethrough.Finger tip 854 advantageously engages against a semiconductor workpiece(see FIG. 41) and assists in holding or fixing the position of theworkpiece relative to workpiece holder 810. Finger tip 854 also assistsin providing an operative electrical connection between the fingerassembly and a workpiece to which an electrical biased is to be appliedand through which current can move. Finger tip 85 can include anelectrode contact 858 for electrically contacting a surface of asemiconductor workpiece once such workpiece is secured as describebelow.

Finger Assembly Drive System Interface

A finger assembly drive system interface is operatively coupled with thefinger assembly drive system to effectuate movement of the fingerassembly between the engaged and disengaged positions. A preferredfinger assembly drive system interface is described with reference toFIGS. 37 and 41. One component of the finger assembly drive systeminterface is a finger actuator 862. Finger actuator 862 isadvantageously provided for moving the finger assembly between theengaged and disengaged position. Finger actuator 862 acts by engagingbearing receptacle 839 and moving finger assembly 824 between an engagedposition and a disengaged position. In the engaged position, finger tip854 is engaged against a semiconductor workpiece. In the disengagedposition finger tip 854 is moved away from the workpiece.

The finger assembly drive system interface includes pneumatic actuator825 (FIG. 37). Pneumatic actuators 825 are operatively connected to anactuation ring 863 and operates thereupon causing the drive plate tomove reciprocally in the vertical direction as viewed in FIG. 37. Fingeractuator 862 is operatively connected to actuation ring 863 in a mannerwhich, upon pneumatic actuation, moves the finger actuator intoengagement with bearing receptacle 839 along the dashed line in FIG. 41.Such allows or enables the finger assembly to be moved longitudinallyalong a first movement path axis 864.

Pneumatic actuator linkage 825 also includes a secondary linkage 865.Secondary linkage 865 is pneumatic as well and includes a link arm 867.Link arm 867 is connected or joined to an actuator torque ring 869.Preferably, torque ring 869 is concentric with rotor 820 (FIG. 38) andcircuitously links each of the finger actuators together. A pneumaticoperator 871 is advantageously linked with the secondary linkage 865 forapplying force and operating the linkage by angularly displacing torquering 869. This in turn rotates the finger assemblies into and away fromthe engaged position.

Preferably finger actuator engagement bits 862, under the influence ofpneumatic linkage 825, moves the finger assembly, and more specificallycollet 840 and finger 848 along a first axial movement path along axis864. The finger actuator engagement bits 862, then under as theinfluence of pneumatic operator 871 are turned about the axes of eachbit like a screwdriver. This moves collet 840 and finger 848 in a secondangular movement. Such second movement turns the fingers sufficiently toproduce the angular displacement shown in FIG. 42. According to apreferred aspect of this invention, such movement of the fingerassemblies between the engaged and disengaged positions takes place whenspin head assembly 814 has been moved 1800 from its FIG. 36 dispositioninto a face-up condition.

The engagement bits 862 can be provided with a purge gas passagetherethrough. Gas is supplied via tube 893 and is passed through thefinger assemblies.

Engaged and Disengaged Positions

FIG. 42 is a view of a portion of a finger assembly, taken along line7-7 in FIG. 39. Such shows in more detail the above-described engagedand disengaged positions and movement therebetween relative to aworkpiece W. In the disengaged position, finger 848 is positionedadjacent the semiconductor workpiece and the finger tip and electrodecontact do not overlap with workpiece W. In the engaged position, thefinger tip overlaps with the workpiece and the electrode is brought tobear against the workpiece. From the disengaged position, fingerassembly 824, upon the preferred actuation, is moved in a firstdirection away from the disengaged position. Preferably, such firstdirection is longitudinal and along first movement path axis 864. Suchlongitudinal movement is linear and in the direction of arrow A as shownin FIGS. 39 and 40. The movement moves the finger assembly to theposition shown in dashed lines in FIG. 39. Such movement is effectuatedby pneumatic operator 825 which operates upon actuation ring 863 (FIG.37). This in turn, causes finger actuator 862 to engage with fingerassembly 824. Such linear movement is limited by angled slot 832 a.Thereafter, the finger assembly is preferably moved in a seconddirection which is different from the first direction and preferablyrotational about the first movement path axis 864. Such is illustratedin FIG. 42 where the second direction defines a generally arcuate pathbetween the engaged and disengaged positions. Such rotational movementis effectuated by secondary linkage 865 which pneumatically engages thefinger actuator to effect rotation thereof. As so moved, the fingerassembly swings into a ready position in which a semiconductor workpieceis ready to be engaged and held for processing. Once the finger assemblyis moved or swung into place overlapping a workpiece, the preferredfinger actuator is spring biased and released to bear against theworkpiece. An engaged workpiece is shown in FIG. 41 after the workpiecehas been engaged by finger tip 854 against a workpiece standoff 865, andspin head assembly 814 has been rotated back into the position shown inFIG.36. Such preferred pneumatically assisted engagement takes placepreferably along movement path axis 864 and in a direction which is intothe plane of the page upon which FIG. 42 appears.

As shown in FIG. 39, finger 848 extends away from collet 840 andpreferably includes a bend 866 between collet 840 and finger tip 854.The preferred bend is a reverse bend of around 180° which serves topoint finger tip 854 toward workpiece W when the finger assembly ismoved toward or into the engaged position (FIG. 42). Advantageously, thecollet 840 and hence finger 848 are longitudinally reciprocally movableinto and out of the engaged position.

Finger Assembly Seal

The finger assembly preferably includes a finger assembly seal 868 whichis effectuated between finger 848 and a desired workpiece when thefinger assembly is moved into the engaged position. Preferably, adjacentfinger tip 854. Seal 868 is mounted adjacent electrode contact 858 andeffectively seals the electrode contact therewithin when finger assembly824 is moved to engage a workpiece. The seal can be made of a suitableflexible, preferably elastomeric material, such as VITON.

More specifically, and referring to FIG. 43, seal 868 can include a rimportion 870 which engages workpiece surface W and forms a sealingcontact therebetween when the finger assembly is moved to the engagedposition. Such seal advantageously isolates finger electrode 860 fromthe processing environment and materials which may plate out orotherwise be encountered therein. Seal 868 can be provided with anoptional bellows wall structure 894 (FIG. 43), that allows more axialflexibility of the seal.

FIG. 43 shows, in solid lines, seal 868 in a disengaged position inwhich rim portion 870 is not engaged with workpiece W. FIG. 43 alsoshows, in phantom lines, an engaged position in which rim portion 870 isengaged with and forms a seal relative to workpiece W. Preferably andadvantageously, electrode contact 858 is maintained in a generallyretracted position within seal 868 when the finger assembly is in thedisengaged position. However, when the finger assembly is moved into theengaged position, seal 868 and rim portion 870 thereof splay outwardlyor otherwise yieldably deform to effectively enable the electrode andhence electrode contact 858 to move into the engaged position againstthe workpiece. One factor which assists in forming the preferred sealbetween the rim portion and the workpiece is the force which isdeveloped by spring 842 which advantageously urges collet 840 and hencefinger 860 and finger tip 858 in the direction of and against thecaptured workpiece. Such developed force assists in maintaining theintegrity of the seal which is developed in the engaged position.Another factor which assists in forming the preferred seal is theyieldability or deformability of the finger tip when it is brought intocontact with the workpiece. Such factors effectively create a continuousseal about the periphery of electrode contact 858 thereby protecting itfrom any materials, such as the preferred plating materials which areused during electroplate processing.

Methods and Operation

In accordance with a preferred processing aspect of the presentinvention, and in connection with the above-described semiconductorworkpiece holder, a sheathed electrode, such as electrode 856, ispositioned against a semiconductor workpiece surface in a manner whichpermits the electrode to impart a voltage bias and current flow to theworkpiece to effectuate preferred electroplating processing of theworkpiece. Such positioning not only allows a desired electrical bias tobe imparted to a held workpiece, but also allows the workpiece itself tobe mechanically held or fixed relative to the workpiece holder. That is,finger assembly 824 provides an electrical/mechanical connection betweena workpiece and the workpiece holder as is discussed in more detailbelow.

Sheathed electrode 856 includes a sheathed electrode tip or electrodecontact 858 which engages the workpiece surface. A seal is thus formedabout the periphery of the electrode tip or contact 858 so that adesired electrical bias may be imparted to the workpiece to enableplating material to be plated thereon. According to a preferred aspectof the processing method, the sheathed electrode is moved in a firstdirection, preferably longitudinally along a movement axis, away from adisengaged position in which the workpiece surface is not engaged by thesheathed electrode tip or contact 858. Subsequently, the sheathedelectrode is rotated about the same movement axis and toward an engagedposition in which the electrode tip may engage, so as to fix, andthereafter bias the workpiece surface. Such preferred movement iseffectuated by pneumatic linkage 825 and pneumatic operator 871 asdescribed above.

According to a preferred aspect of the invention, the seal which iseffectuated between the sheath tip and the workpiece is formed byutilizing a yieldable, deformable sheath tip or terminal end 868 whichincludes a sheath tip rim portion 870. The sheath tip rim portion 870advantageously splays outwardly upon contacting the workpiece surface toform a continuous seal about the periphery of the electrode tip as shownin FIG. 8. The preferred electrode tip is brought into engagement withthe workpiece surface by advancing the electrode tip from a retractedposition within the sheath tip to an unretracted position in which theworkpiece surface is engaged thereby. Such movement of the electrode tipbetween the retracted and unretracted positions is advantageouslyaccommodated by the yieldable features of the sheath tip or terminal end868.

In addition to providing the preferred electrical contact between theworkpiece and the electrode tip, the finger assembly also forms amechanical contact or connection between the assembly and the workpiecewhich effectively fixes the workpiece relative to the workpiece holder.Such is advantageous because one aspect of the preferred processingmethod includes rotating the workpiece about rotor axis 822 while theworkpiece is exposed to the preferred plating material. Such not onlyensures that the electrical connection and hence the electrical biasrelative to the workpiece is maintained during processing, but that themechanical fixation of the workpiece on the workpiece holder ismaintained as well.

The above described pneumatically effectuated movement of the preferredfinger assemblies between the engaged and disengaged positions is butone manner of effectuating such movement. Other manners of effectuatingsuch movement are possible.

Methods Re Presenting Workpiece

The invention also includes novel methods for presenting a workpiece toa semiconductor process. In such methods, a workpiece is first securedto a workpiece holder. The methods work equally well for workpieceholders known in the art and for the novel workpiece holders disclosedherein.

In the next step in the sequence, the workpiece holder is rotated abouta horizontal axis from an initial or first position where the workpieceholder was provided with the workpiece to a second position. The secondposition will be at an angle to the horizontal. The angle of theworkpiece holder to the horizontal is defined by the angle between theplane of the workpiece and the horizontal. In the method, the workpieceholder is advantageously suspended about a second horizontal axis whichis parallel to the first horizontal axis of the workpiece holder. Atthis point in the method, the angle between the first and secondhorizontal axes and a horizontal plane corresponds to the angle betweenthe workpiece holder and the horizontal. The workpiece holder is thenpivoted about the second horizontal axis to move the workpiece and theworkpiece holder from its initial location to a final location in ahorizontal plane. Advantageously, when the workpiece holder is pivotedabout the second horizontal axis, the first horizontal axis also pivotsabout the second horizontal axis.

Preferably, during the step of rotating the workpiece holder about thefirst horizontal axis, the angle of the workpiece holder with respect tosome known point, which is fixed with respect to the workpiece holderduring the rotation process, is continually monitored. Monitoring allowsfor precise positioning of the workpiece holder with respect to thehorizontal surface.

Likewise, during pivoting of the workpiece holder about the secondhorizontal axis, it is preferable that the angle defined by the lineconnecting the first and second horizontal axes and the horizontal planebe continually monitored. In this manner, the absolute position of theworkpiece holder (and hence the workpiece itself) will be known withrespect to the horizontal plane. This is important since the horizontalplane typically will contain the process to which the workpiece will beexposed.

It should be noted that in the above and following description, whilethe workpiece is described as being presented to a horizontal plane, itis possible that the workpiece may also be presented to a vertical planeor a plane at any angle between the vertical and the horizontal.Typically, the processing plane will be a horizontal plane due to thedesire to avoid gravitational effects on process fluids to which theworkpiece is exposed. In one embodiment after the workpiece has beenpresented to the processing plane, the workpiece holder is rotated abouta spin axis to cause the workpiece to spin in the horizontal plane.Although not required in all semiconductor manufacturing processes, thisis a common step which may be added in the appropriate circumstance.

The next advantageous step in the method consists of pivoting theworkpiece holder about the second horizontal axis back along the paththat the workpiece holder was initially pivoted along when presentingthe workpiece to the horizontal process plane. There is no requirementthat the workpiece holder be pivoted back to the same position whence itbegan, although doing so may have certain advantages as more fullydescribed below.

The method advantageously further consists of the step of rotating theworkpiece holder about the first horizontal axis to return the workpieceto the position when it was initially presented to and engaged by theworkpiece holder. It is advantageous to rotate the workpiece holderabout the first axis in a direction opposite from the initial rotationof the workpiece holder.

The advantage of having the workpiece holder terminate at an endposition which corresponds to the initial position when the workpiecewas loaded into the workpiece holder is efficiency. That is, additionalmachine movements are not required to position the workpiece holder toreceive a new workpiece.

The method more preferably includes the step of rotating the workpieceholder about the first horizontal axis at at least two support pointsalong the first horizontal axis. This beneficially provides support andstability to the workpiece holder during the rotation process andsubsequent movement of the apparatus.

The method also more preferably includes the step of pivoting theworkpiece holder along with the first horizontal axis about the secondhorizontal axis at at least two support points along the secondhorizontal axis. This beneficially provides additional support for theworkpiece holder while allowing the workpiece holder to be moved in avertical or “Z-axis” direction.

Importantly, the only motion described in the above method is rotationalmotion about several axes. In the method described, there is notranslational motion of the workpiece holder in a X-, Y-, or Z-axiswithout corresponding movement in another axis as a result of rotatingthrough an arc.

Electroplating Processing Station

The workpiece process tool may comprise several different modules forperforming a variety of manufacturing process steps on the workpiece orsemiconductor wafer. The workpiece processing tool may advantageouslycontain electroplating module 20, alternately known more generally as aworkpiece processing station.

The plating module 20 of FIG. 44 is shown as a 5 bay plating module.This allows for up to 5 workpieces to be processed simultaneously. Eachof the 5 electroplating bays may alternately be known as a workpieceprocessing station. Each workpiece processing station is advantageouslyprovided with a workpiece support 401. Each workpiece support is furtheradvantageously provided with a processing head 406, an operator arm 407,and an operator base 405. The details of the workpiece support 401 aredescribed below. The operator base 405 of the workpiece support 401 ismounted to the workpiece processing station by securing it to thechassis or shelf of the workpiece module.

Workpiece support 601 is shown in a “open” or “receive wafer” positionwhereby a robotic arm or other means will provide a workpiece to theworkpiece support. The workpiece support will positively engage theworkpiece (described more fully below) by fingers 409 (or moreprecisely, by finger tips of finger assemblies, which are also describedmore fully below). The processing head 406 will then rotate about theoperator arm 407 to place the workpiece in an essentially downwardfacing position. Operator arm 407 will then pivot about operator base405 to place the workpiece in the processing bowl as shown at 602 ofFIG. 2. The manufacturing step or process will then be performed uponthe workpiece. Following the manufacturing step, the workpiece will bereturned to the open position shown by workpiece support 601 at whichtime the workpiece will be removed from fingers 409.

Although the invention is described for an electroplating process, it isto be noted that the general arrangements and configurations of theworkpiece processing stations and their combination into amulti-workpiece processing station unit may be applied to a variety ofprocesses used in manufacturing.

FIG. 44 also shows an optional beam emitter 81 for emitting a laser beamdetected by robotic wafer conveyors (not shown) to indicate position ofthe unit.

Turning to FIG. 45, an isometric view of the electroplating module 20with the front panel cut away reveals that the module is advantageouslyprovided with a series of process bowl assemblies or plating chamberassemblies 603, a process fluid reservoir 604, and an immersible pump605. Each process bowl assembly 603 is connected to the immersible pump605 by fluid transfer lines which preferably are provided withinstrumentation and control features described more fully below.

The details of the bowl assemblies and their arrangement andconfiguration with the other components of the invention describedherein are described more fully below.

The process fluid reservoir 604 is mounted within the processing module20 by attaching it to the module frame or chassis 606. Turning to FIG.4, the fluid reservoir 604 is shown in isolation with process bowlassembly 603, immersible pump 605, and pump discharge filter 607.

Turning briefly to FIG. 49, a side sectional view of the fluid reservoir604 is shown. As can be seen in FIG. 49, process fluid reservoir 604 isadvantageously a double-walled vessel having an outer reservoir wall 608and an inner reservoir wall 609 defining a reservoir safety volume 611therebetween. Fluid reservoir 604 is preferably a double-walled vesselin the event that the inner wall 609 should leak. A double-walled vesselconstruction design would allow the leak to be contained within thereservoir safety volume 611 between the outer wall 608 and the innerwall 609. Should the reservoir safety volume become filled with fluidleaking from the inner vessel 612, the fluid would overflow throughreservoir overflow opening 610. Reservoir opening 610 is preferablyprovided with guttering or the like to channel overflow fluid to a safecollection point (not shown). Further, the reservoir safety volume maybe provided with liquid detection sensors (not shown) to alert operatorsin the event that the inner wall of reservoir 604 should become breachedand fluid enter the reservoir safety volume 611.

The process module may also be provided with a heat exchanger 613.Turning to FIG. 48, the heat exchanger 613 is shown in front elevationview of the process fluid reservoir 604. The heat exchanger shown inFIG. 48 is a double helix-type having an exchanger inlet 614 and anexchanger outlet 615. The exchanger 613 may be used for either coolingor heating the process fluid by circulating respectively either a cooleror warmer fluid through the exchanger than is present in the reservoir.Alternate designs of heat exchangers may also effectively be used in theapparatus of the present invention.

Bowl Assembly

Returning to FIG. 46, a plurality of bowl assembly 603 are shown mountedin reservoir top 618. The indicated process chamber 603 is shown inisometric detail in FIG. 47.

Turning to FIG. 47, it is seen that the bowl assembly 603 is securedwithin reservoir top 618. The process bowl assembly consists of aprocess bowl or plating chamber 616 having a bowl side 617 and a bowlbottom 619. The process bowl is preferably circular in a horizontalcross section and generally cylindrical in shape although the processbowl may be tapered as well.

The invention further advantageously includes a cup assembly 620 whichis disposed within process bowl 616. Cup assembly 620 includes a fluidcup 621 having a cup side 622 and a cup bottom 623. As with the processbowl, the fluid cup 621 is preferably circular in horizontal crosssection and cylindrical in shape, although a tapered cup may be usedwith a tapered process bowl.

Process fluid is provided to the process bowl 616 through fluid inletline 625. Fluid inlet line rises through bowl bottom opening 627 andthrough cup fluid inlet opening 624 and terminates at inlet line endpoint 631. Fluid outlet openings 628 are disposed within the fluid inletline 625 in the region between the cup fluid inlet opening 624 and fluidline end point 631. In this way, fluid may flow from the fluid inletline 625 into the cup 621 by way of the inlet plenum 629.

The cup assembly 620 preferably includes a cup filter 630 which isdisposed above the fluid inlet openings and securely fits between theinner cup wall 622 and the fluid inlet line 625 so that fluid must passthrough the filter before entering the upper portion of cup 621.

In an electroplating process, the cup assembly 620 is advantageouslyprovided with a metallic anode 634. Anode 634 is secured within the cupassembly by attaching it to the end point 631 of the fluid inlet line.Anode 634 is thus disposed above the cup filter 630 as well as abovefluid inlet opening 628. Anode 634 is preferably circular in shape andof a smaller diameter than the inside diameter of cup 621. Anode 634 issecured to the end point 631 of fluid inlet line 625 so as to center theanode 634 within cup 621 creating an annular gap or space 635 betweenthe inner cup wall 622 and the edge of anode 634. Anode 634 should be soplaced such as to cause the anode annular opening 635 to be of aconstant width throughout its circumference.

The outer cup wall 636 is advantageously of a smaller diameter than theinside diameter of bowl 616. Cup assembly 620 is preferably positionedwithin bowl 616 such that a first annular space or process fluidoverflow space 632 is formed between bowl side 617 and cup outer wall636. The cup assembly is more preferably positioned such that theannular fluid overflow space 632 is of a constant width throughout itscircumference.

Cup assembly 620 is further advantageously positioned within bowl 616such that cup upper edge 633 is below bowl upper edge 637. Cup 621 ispreferably height-adjustable with respect to bowl upper edge 637, asmore fully described below.

Bowl bottom 619 is preferably configured so as to have a large open areaallowing the free transfer of fluid therethrough. In the preferredembodiment, this is achieved by the structure shown in FIG. 47 whereinthe process bowl bottom 619 is composed of crossbars 626 which intersectat bowl bottom center plate 639 creating fluid return openings 638. Bowlbottom center plate 639 is provided with bowl bottom opening 627 toallow fluid inlet line 625 to pass therethrough. In the preferredembodiment, the bowl sides 617 below the reservoir top 618 are alsosimilarly constructed so that bowl sides below reservoir top 618 areessentially composed of 4 rectangular sections which then turn inwardtowards bowl bottom center plate 639 intersecting thereat. Such aconfiguration allows for a high degree of fluid flow to pass through thebowl lower portion which is disposed within reservoir 604.

Thus, operation, process fluid is provided through process fluid inletline 625 and discharges through fluid outlet openings 628 within thelower part of the cup assembly 620. By virtue of cup filter 620, fluidentering the fluid inlet plenum 629 is distributed across the plenum andthen flows upward through filter 630 to the bottom of anode 634.

From the top side of filter 630, the process fluid continues to flow inan upward direction by virtue of continuing feed of process fluidthrough process inlet line 625. The process fluid flows around theannular gap 635 between the anode 634 and the inner cup wall 622. As theprocess fluid continues to well up within cup 621, it will eventuallyreach upper cup edge 633 and will overflow into the overflow annular gap632 between the outer cup wall 636 and the inner wall of bowl 616.

The overflowing fluid will flow from the overflow gap 632 downwardthrough the gap and back into reservoir 604 where it will be collectedfor reuse, recycling, or disposal. In this manner, no process fluidreturn line is required and no elaborate fluid collection system isnecessary to collect surplus fluid from the process.

As a further advantage, the location of the cup filter 630 and anode 634within the cup 621 provides an even distribution of fluid inlet into thecup. The even distribution beneficially assists in providing a quiescentfluid surface at the top of cup 621. In like manner, maintaining aconstant distance between the outer wall of cup 636 and the inner wallof bowl 616 in providing the overflow gap 632 will assist in providingan even flow of fluid out of cup 621 and into the reservoir 604. Thisfurther beneficially assists in providing the desired quiescence stateof the process fluid at the top of cup 621.

The material selection for cup filter 620 will be dictated by theprocess and other operating needs. Typically, the filter will have thecapability of filtering particles as small as 0.1 microns. Likewise, thechoice of materials for anode 634 will be dictated by the desired metalto be electroplated onto the workpiece.

While the above bowl assembly has been described particularly for anelectroplating process, it can be seen that for a process where a flowof fluid is required but no anode is required removing the anode 634from the cup assembly 603 will provide a quiescent pool of liquid forthe process. In such an arrangement, the end point 631 of the fluidinlet line 625 would be capped or plugged by a cap or plug rather thanby the anode 634.

To assist in ensuring that process fluid overflows into the annular gap632 evenly, it is necessary to ensure that the cup upper edge 633 islevel such that fluid does not flow off of one side of cup 621 fasterthan on another side. To accomplish this objective, levelers arepreferably provided with the process bowl assembly 603.

Turning now to FIG. 50, the process bowl assembly of FIG. 47 is shown incross section along with the workpiece support 401. The process bowlassembly 603 is shown mounted to the process module deck plate 666.Plating chamber assembly 603 is preferably provided with levelers 640(only one of which is shown in this view) which allow the platingchamber assembly to be leveled relative to the top of reservoir 618. Thelevelers may consist of jack screws threaded within the edge of moduledeck plate 666 and in contact with the process module frame 606 so as toelevate the process bowl assembly 603 relative to the process module 20.The process bowl assembly 603 is preferably provided with three suchbowl levelers distributed about the bowl periphery. This allows forleveling in both an X and Y axis or what may be generically described as“left and right leveling and front and rear leveling.”

Since process bowl assembly 603 is free to move with respect to fluidreservoir 604, when process bowl assembly 603 is fit closely withinfluid reservoir 604 as shown in FIG. 50, the process bowl/fluidreservoir junction preferably has a compliant bowl seal 665 disposedtherebetween to allow movement of the process bowl 616 with respect toreservoir inner wall 609. Compliant seal 665 further prevents processfluid from passing through the opening between the process bowl and thereservoir wall.

Cup assembly 620 is preferably provided with cup height adjuster 641.The cup height adjuster shown and described herein consists of a cupheight adjustment jack 643 which is positioned about an externallyportion of inlet line 625. Cup 621 is secured to cup height adjustmentjack 643 with cup lock nut 642. Cup lock nut 642 is used to secure cup621 in its height position following adjustment. The upper end of cupheight adjustment jack 641 is provided with adjustment tool access holes667 to allow for adjusting of the height of the cup from the top of thebowl rather than the underside. The cup height adjuster 641 mayadditionally be provided with a fluid seal such as an o-ring (not shown)disposed within the annular space formed between the adjsutment jack 643and the cup bottom 623.

The process bowl assembly 603 is more preferably provided with anadditional height adjuster for the anode 634. Since it is desirable tobe able to adjust the distance between the anode 634 and the workpiecebased upon the particular electroplating process being used, anodeheight adjuster 646 is beneficially provided. Anode height adjuster 646is formed by mounting the anode 634 on the threaded anode post 664. Athreaded anode adjustment sleeve 663 is used to connect the threadedupper end of inlet line 625. Anode adjustment sleeve 663 is providedwith sleeve openings 668 to allow fluid to pass from fluid outletopenings 628 into the inlet plenum 629. The space between the bottom ofanode post 664 and the upper end of fluid inlet line 625, and bounded bythe anode adjustment sleeve 663, defines a fluid outlet chamber 662.Fluid outlet chamber is of variable volume as the anode post 664 movesupward and downward with height adjustment of the anode 634.

On the bowl leveler 640 and the height adjusters 641 and 646 describedabove, it is additionally desirable to provide them with lockingmechanisms so that once the desired positioning of the device (i.e., thebowl, the cup, or the anode) is achieved, the position may be maintainedby securing the adjusters so that they do not move out of adjustment asa result of vibration or other physical events.

Allowing independent height adjustment of the cup and anode each withrespect to the bowl provides a large degree of flexability in adjustingthe process bowl assembly 603 to accomodate a wide selection ofprocesses.

Fluid Transfer Equipment

To provide process fluid to the process bowl assembly in theelectroplating module of the present invention, the module isadvantageously provided with fluid transfer equipment. The fluidtransfer equipment is provided to draw process fluid from a reservoir,supply it to the process bowl assemblies, and return it to a commoncollection point.

Turning now to FIG. 48, a cross section of the reservoir and processbowl assemblies and additional equipment shown in FIG. 46 is shown. FIG.48 shows a immersible pump 605 which is mounted to the reservoir top618. The plating module is advantageously provided with such a pumpwhich further consists of a fluid suction or pump suction 647 whichdraws process fluid from the reservoir 604. The immersible pump pumpsfluid from the pump suction 640 into the pump body 653 and out throughthe fluid discharge or pump discharge 648. Immersible pump 605 ispreferably driven by an electric pump motor 650.

In alternate embodiments of the present invention, a submersible pumpmay be deployed. However, the immersible pump has the advantage that itmay be easily removed for servicing and the like. In yet anotherembodiment, individual pumps for each of the process bowl assemblies maybe deployed or, process bowls assemblies may share a set of commonpumps. Each such pump would have a process fluid inlet suction and aprocess fluid discharge.

Returning to the preferred embodiment of FIG. 48, the plating modulepreferably has a pump discharge filter 607 which is connected in linewith pump discharge 648. Pump discharge filter 607 is preferablyprovided with a removable filter top 649 so that filter cartridgeswithin the filter may be replaced. The filter type, size and screen sizewill be dictated by the needs of the particular process being deployedat the time.

From the pump discharge filter 607, the process fluid exits throughfilter outlet 651 and into supply manifold 652. The supply manifoldsupplies all of the process bowl assemblies 603 with process fluid.Branching off from the supply manifold 652 are the individual fluidinlet lines 625. The fluid inlet lines 625 are preferably provided withflow control devices which are more fully described below.

At the down stream end of the supply manifold 652 after the finalprocessing bowl assembly 661, the manifold is routed to fluid returnline 654. Although the supply manifold could be terminated at an openended point at optional end point 655, in the preferred embodiment, thesupply manifold 652 is additionally provided with a back pressureregulator 656, which is described more fully below. Since it isadvantageous to have the back pressure regulator outside of the fluidreservoir for ease of access, the fluid return line 654 is provided whenthe back pressure regulator 656 is employed.

Control Devices

In the preferred embodiment, the work station processing module of thepresent invention further includes devices for controlling the flow anddistribution of the process fluid to the process bowl assemblies.

With reference to FIG. 48, the apparatus of the present invention isbeneficially provided with flow sensors 657 which are disposed withinthe fluid inlet line 625 for each individual process bowl assembly 603.The flow sensors 657 will measure the amount of process fluid flowingthrough each fluid inlet line and will generate a signal which will betransmitted by flow signal line 659. A signal will typically be anelectrical signal but may also be a pneumatic or other type of signal.

The processing modules 603 are also preferrably provided with flowrestrictors 658 which are disposed in fluid inlet lines 625 after theflow sensor 657 but before the fluid outlet opening 628 within cup 621(shown in FIG. 47). The flow restrictor may alternately be known as avariable orifice or a control valve. The flow restrictor 658 may eitherbe manually adjustable, or may be responsive to a signal provided byflow control signal line 660. The flow control signal line may be apneumatic, electrical or other type of signal. The objective of the flowcontroller is to control the quantity of process fluid being provided tothe fluid cup 621 during the processing step of manufacturing thesemiconductor. When the flow restrictor is responsive to a controlsignal, the information provided from the flow signal line 659 may beused to modify or generate the flow control signal which is thenprovided to the flow controller 658. This control may be provided by amicro processor or by other control devices which are commerciallyavailable.

More preferably, the semiconductor processing module is provided withback pressure regulator 656. As pump discharge filter 607 becomesrestricted due to captured filtrate, the pressure within supply manifold652 will drop, reducing flow of process fluid to the fluid cups 621.Back pressure regulator 656 is used to maintain a preselected pressurein the supply manifold 652 to ensure that sufficient pressure isavailable to provide the required flow of process fluid to the fluidcups. Back pressure regulator 656 further comprises an internal pressuresensor and preferably includes a signal generator for generating acontrol signal to open or close the back pressure regulator to increaseor decrease the pressure in the supply manifold. The back pressureregulator may be controlled by an external controller such as a microprocessor or it may have a local set point and be controlled by aninternal local control mechanism.

In an alternate embodiment, where a dedicated process pump is used foreach process bowl assembly, a back pressure regulator would typicallynot be required.

Plating Methods

The present invention also includes a novel method for processing asemiconductor workpiece during manufacturing.

In the preferred embodiments of the method, a semiconductor workpiece orwafer is presented to the semiconductor manufacturing process. This maybe accomplished by use of the workpiece support 401 shown in FIG. 50 anddescribed more fully herein. FIG. 51 shows the workpiece W beingpresented to the process. At the time that the workpiece is presented tothe process, the process fluid, which in an electroplating process is anelectrolytic solution, is cause to flow within a processing chamber(herein the cup 621) to the workpiece. This assures that a sufficientquantity of fluid is available for the required process step.

The workpiece W is preferably presented to the process in a preciselylocated position so that all surfaces of the workpiece are exposed tothe solution. In an electroplating process, it is advantageous to exposeonly the downward facing or working surface of the wafer to theelectrolytic solution and not the backside of the wafer. This requiresaccurate positioning of the wafer with respect to the fluid surface. Inan electroplating process, the method also requires the step ofaccurately positioning the workpiece with respect to the anode 634 sothat the anode and workpiece are separated by an equal distance at allpoints.

Once the workpiece has been positioned as the process may specificallyrequire, the next step in the method is performing the actual processingstep itself. For example, in an electroplating application, theprocessing step would include applying an electric current to theworkpiece so as to generate the current through the electrolyticsolution thereby plating out a layer of a desired metallic substance onthe wafer. Typically a current will be applied to the anode as well,with a negative current being applied to the workpiece. The processingstep is applied for the length of time which is dictated by the processitself.

The process further includes the step of continuing a flow of theprocess fluid such that the process fluid overflows the processingchamber and falls under gravitational forces into a process fluidreservoir. Preferrably the process fluid reservoir is the same reservoirwhich provides the process fluid or solution to the process.

As an additional step in the method of processing the semiconductorwafer in the electroplating process, the method includes the furtherstep of spinning or rotating the workpiece about a vertical axis whileit is exposed to the electrolytic solution. The rate of rotation variesbetween about 5 and 30 rpm and is more preferably approximately 10 rpm.The rotation step provides the beneficial result of additional assuranceof even distribution of the electrolytic solution across the face of theworkpiece during the electroplating process.

After the processing has been performed on the semiconductor wafer, themethod advantageously includes the step of removing the workpiece fromthe process and returning it to a position where it may be removed forfurther processing or removal from the semiconductor workpiece processtool.

The method preferably includes the step of performing theabove-described steps at a series of process bowls having a common fluidreservoir such that the overflowing fluid gravity drains into a commonfluid reservoir.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1-4. (canceled)
 5. A head assembly for holding a microelectronicworkpiece in electrochemical processing, comprising: a motor having arotor axis; a support coupled to the motor to rotate about the rotoraxis, the support being configured to carry a microelectronic workpiecefacedown in a workpiece processing plane generally normal to the rotoraxis; and a plurality of electrical contacts carried by the support, theelectrical contacts having first sections outside of a workpiece zonewhere a workpiece is positioned relative to the support and secondsections projecting from the first sections into a perimeter area of theworkpiece zone, wherein individual second sections of the electricalcontacts have (a) an inclined portion extending at an inclined anglerelative to the workpiece processing plane and (b) a conductive contactregion configured to press against a surface of the workpiece upon whichelectrochemical processing is to occur.
 6. The head assembly of claim 5wherein the first sections of the electrical contacts project from thesupport member to a level beyond the workpiece processing plane and thesecond sections project from the first sections toward the workpieceprocessing plane.
 7. The head assembly of claim 5 wherein the inclinedportions of the second sections of the electrical contacts are slopedtoward the workpiece processing plane.
 8. A tool for electrochemicalprocessing of microelectronic workpieces, comprising: a chamber; a headassembly aligned with the chamber, the head assembly including a motorhaving a rotor axis, a support coupled to the motor to rotate about therotor axis, and a plurality of electrical contacts carried by thesupport, wherein the support is configured to carry a microelectronicworkpiece facedown in a workpiece processing plane generally normal tothe rotor axis, and the contacts have first sections outside of aworkpiece zone where a workpiece is positioned relative to the supportand second sections projecting from the first sections, and whereinindividual second sections of individual electrical contacts have (a) aninclined portion extending at an inclined angle relative to theworkpiece processing plane and (b) a conductive contact regionconfigured to press against a surface of the workpiece upon whichelectrochemical processing is to occur.
 9. The tool of claim 8 whereinthe first sections of the electrical contacts project from the supportmember to a level beyond the workpiece processing plane and the secondsections project from the first sections toward the workpiece processingplane.
 10. The tool of claim 8 wherein the inclined portions of thesecond sections are sloped toward the workpiece processing plane.